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What's up everybody? In this video, I'm

going to teach you everything you need

to know to start coding with Python.

I've also included 20 different hands-on

projects to help you learn. You can find

the entire list in the description of

this video. Our final project will be a

weather app that fetches real-time

weather data from an API. Even if you've

never coded anything in your life

before, I'll walk you through the

basics, the ABCs of programming. If that

sounds good to you, then I encourage you

to sit back, relax, and enjoy the

show. This course doesn't cost you

anything, but if you would like to help

me out, you can help increase its reach

by hitting the like button, leave a

random comment down below, and subscribe

if you'd like to be a fellow bro. Thank

you. I appreciate it. I don't like

boring introductions, so I say we just

jump right in. There's two things we'll

need to download. The first is a Python

interpreter to convert our written code

to machine code. We're going to head to

python.org, go to

downloads, and download the latest

version. We will open this

executable. If you're on Windows, you'll

want to check this check box, add Python

exe to path, and we will install now.

The setup was successful. And that's all

you need to do to download the Python

interpreter. The second download we'll

need is an IDE, an integrated

development environment. Basically, a

place where we can write code. For

IDEES, there's two popular choices when

writing Python code. PyCharm and VS

Code. If you already use VS Code, you

can stick with that. Just be sure to

download the Python extension. I find

PyCharm more beginner friendly if you've

never coded before. If you would like to

use PyCharm, go to

jetbrains.com/pycharm. And we will click

this green download

button. There's two versions of PyCharm,

the professional version and the

community version. The professional

version is paid for. I would not

recommend using it only because there's

plenty of free IDE on the market. We'll

use the community edition, the free one,

because I don't like to pay for things

and I'm sure you don't either. Select

the correct download for your operating

system. I'm running Windows. I will

download

PyCharm. We will open this

executable. Click next. You could select

a destination folder. I'll keep it as

is. Next, I'll create a desktop

shortcut, but you don't necessarily need

to. Click

next. Install. And we'll just have to

give it a

moment. Okay, the setup is now complete.

I'll check this checkbox to run PyCharm

when we close this

window. After opening PyCharm, we're

going to create a new

project. You can rename your Python

project. I'll keep it as is. You can

select a location. Again, I won't change

that. You can create a sample welcome

script, but for this tutorial, we won't.

Let's select the latest Python

version and create our new

project. In the menu to the left, we're

going to create a new Python file. File,

new, Python

file. Let's name this file main.

But really you can name it anything and

select Python

file. Python files end with the py file

extension. We should have our main

Python file within our Python project

folder. Now we're going to print

something to the console window. Within

our main Python file, we're going to

write a print statement. So type print

add a set of parenthesis. Between the

set of parenthesis, we will add a set of

double quotes to print something or

single quotes. Either one. My own

preference is double quotes. Normally in

a programming tutorial, the instructor

would tell you to print something such

as hello world, but we like to be

different

here. Instead, think of your favorite

food. In this case, I like pizza. I will

print I like pizza.

To run our Python program, we will click

the screen arrow to run our main Python

file. We should have a console window

that displays our output. I like pizza

or whatever your favorite food is. Let's

print another line of code.

Let's

print it's really

good. By adding a second print

statement, we are printing a second line

of

code. Now we'll discuss

comments. The Python interpreter doesn't

output comments. To write a comment, you

use a pound sign. I like to call this a

hashtag. My comment will be this is my

first Python

program. Comments are used as notes for

yourself or for other people reading

this code. If I were to run this code

again, this comment is not displayed to

the output. We still have I like pizza.

It's really good. All right, everybody.

So, that is your very first Python

program. And in the next topic, we'll

discuss variables.

All right, everybody. We are moving on

to variables. A variable is a container

for a value. There's four different data

types. We'll discuss strings, integers,

floats, and booleans. Yes, I know that's

a silly name. A variable behaves as if

it was the value it contains. Each

variable should have a unique name.

Let's say we have a variable of first

name. To assign a variable, you use the

assignment operator of equals. For text,

a string is a series of text. This can

be double quotes or single quotes. My

own preference is double quotes. Why

don't you type in your first name? This

variable of first name will behave as if

it was this value, this series of

characters. So to demonstrate this, I'm

going to print my first name

variable. So place it within a print

statement without quotes. That will

print your first name. Now, you don't

want this within

quotes because then you're literally

printing the word first

name. You could use your variable along

with some text by using what is called

an F string. That's the easiest way to

display a variable. So, you type F then

a set of quotes. The F means

format. So, let's say the word hello.

Then we will add our variable. We will

insert our variable into this text when

using an F string. To do that, you need

a set of curly braces. Then insert your

variable. So the result is hello,

whatever your first name is. In my case,

bro. Let's create another

variable. Let's say we have a variable

of food. Food equals think of your

favorite food. For me, I will type

pizza.

Let's print the

following. You like add a placeholder.

Again, I'm using an F

string. Our variable of food. Hello,

bro. You like

pizza. Let's create an

email. Use your own email or make up

one. Let's say my email is

bro123@fake.com.

Then let's print our

email. Your email is add a placeholder.

Display our email

variable. Your email is

bro123@fake.com. So these are strings.

I'm going to add a comment that these

are strings. A string is a series of

characters. They can include numbers but

we treat them as

characters. Now we have

integers. An integer is a whole number.

An example of this could be somebody's

age. How old are they? According to my

YouTube statistics, many of you are

between the ages of 18 through 24. Let's

say that I'm

25. Let me zoom in a little. Your

integer should not be within quotes

because it would be a string. Then

technically if I would like to work with

this variable again I'll use an f

string. Let's say you are add a

placeholder display our age

variable years

old. You are 25 years old.

Another example of an integer could be a

quantity. You are buying a certain

amount of something. Maybe I am buying

three items. I wouldn't have half an

item. This would be a float technically

rather than an integer. We are buying

three of

something. So let's print the

following. You are

buying. Add a placeholder.

display our

quantity

items. You are 25 years old. You are

buying three

items. Another example of an integer

could be an amount of people. Let's say

num of students like a

classroom. There are 30 students in our

class.

Then we will

print your class has add a

placeholder students. We will display

the number of students. Num of

students. Your class has 30

students. Those are integers. They're

whole numbers. And again, make sure

they're not within quotes because then

technically they would be a string.

integers we can use in arithmetic

expressions. If they were strings, we

couldn't. Then we have floats. Float

means floatingoint

number. A float is a number, but it

contains a decimal portion. An example

would be a price. What is the price of

something?

$10.99. Let's print our price. Print.

I'll use an F string. The price is add a

placeholder. display our

price. The price is

$10.99. Let's preede our placeholder

with a unit of currency. I'll pick

American dollars, but feel free to pick

something else. The price is

$10.99. So, floats contain a decimal

portion. What about a grade point

average

GPA? Let's say my GPA is 3.2.

Then I will print your GPA

is display our

GPA. Your GPA is

3.2. What about a distance? A distance

can contain a decimal portion.

5.5 kilometers maybe.

Then I will

print you ran. Add a placeholder.

Display our distance. Then I'll add km

for kilometers. Or you could add mi for

miles, but I'll stick with

kilome. You rand 5.5

km. Okay. Then we have booleans. A

boolean is either true or

false. Let's say we're a student. is

student equals. If we are a student, we

could say that this is true. True starts

with a capital T. If we weren't a

student, let's say we graduate, we could

say that this is false. Again, the first

letter is capital. Booleans only have

two options, true or false. So, let's

say that I am a

student. Then I will

print are you a student?

Then we will display our boolean value

of is

student. Are you a student? That is

true. With boolean values, we really

don't output them directly. You're more

likely to see them used internally

within a program, such as when working

with if statements. This is a topic

we'll discuss in the future, so don't

worry. You may see if is student. If

this variable is true, then we will

print the

following. Now, we don't need to use an

string. We're not going to insert any

variables. You are a student. If this

were false, we can add an else

clause where we will

print you are not a

student. Our variable of is student is

true. We will print the if statement.

You are a student. If this were false,

we will print whatever is within

else. You are not a student. Let's think

of a few more

examples. Is something for sale like a

car or a product of some sort? Let's say

that is true. I'll write another if

statement. If for sale, if this variable

contains true, we will do the following.

Let's

print that item is for

sale. Else if it's false, we will print

something

else. That item is not

available. For sale is set to

true. This variable is true. We will

print that item is for sale. else if it

were

false we print that item is not

available.

One more example. Let's say we have a

boolean variable of is online. Is

somebody online? I will set that to

true. If is online. If that's true, we

will print you are

online. Else we will

print you are

offline. Is online is set to true. We

will print you are online. else if it

were false we print you're

offline. All right everybody so those

are variables. A variable is a reusable

container for a value. There's four

basic data types for beginners. A string

which is a series of text, integers

which are whole numbers, floats which

are numbers but they contain a decimal

portion and booleans which are either

true or false. They're binary. Your

assignment in the comment section is to

post four variables. Post a string, an

integer, a float, and a boolean. Try and

think of a unique example if you can.

And well everybody, those are variables

in

Python. All right everybody, so we are

moving on to type casting. Typ casting

is the process of converting a variable

from one data type to another. We have

various functions to convert a value or

variable to a string, an integer, a

float or a boolean. Let's create some

variables. We will create a name

variable. Type in your full

name, an age, make up some

age, a GPA for grade point average,

let's say minus

3.2, and a boolean of is student. Are we

currently a student? Let's say that's

true. Now, you actually could get the

data type of a variable or a value by

using the type function. Then pass in a

value or variable. However, when I run

this, there's no output. So, I need a

print statement. We will print what is

returned by the type function. Get the

type of our name variable, then print

it.

So our name variable is a string

str. Our age

variable is an integer and

int GPA is a

float is student is a boolean. Using

these type cast functions we can convert

from one data type to another. Here's

how. Let's start with something simple.

Let's convert our GPA to an integer.

Currently, it's a float. I will reassign

GPA. Use the int function to type cast

to an integer. Then pass in my GPA. At

the end, we will print our

GPA. If we type cast 3.2 to a whole

integer, what would the result be? A

whole integer of three. We truncate the

decimal

portion. Let's convert our age to a

floatingoint number. We will reassign

our variable of

age. Use the type cast function a float.

Then insert our age

variable. Let's print our age

variable. And it should be a floating

point number

25.0. Now we'll cover strings. Let's

type cast our age to be a string. age

equals call the type cast function of

string str pass in our age

variable. So the result is still going

to appear the

same 25. However, it's a string not an

integer. And to prove that I will

enclose my age variable with the type

function. The type of variable age is a

string.

It would be the same as if we're taking

this number and enclosing it within

quotes. So this would make a difference

because let's say that I add one to age.

Age plus equals

1. Well, we would get a type error. Can

only concatenate strings, not integers

to a

string. However, if I were to add a

string of one to the end, we would be

using string concatenation. So let's say

it's my birthday and I add 1 to 25.

Well, since we're working with strings

now, the result would be 251. I am 251

years

old. So strings and numbers behave

differently. With numbers, we can use

them within arithmetic expressions.

Strings, not so much. We will take our

name variable and type cast it to a

boolean.

name equals call the typcast function of

bool pass in our name

variable. This has an interesting

result. So I'm going to print name.

Booleans are either true or false. If I

type cast my string of text into a

boolean that gives me

true. Now it really doesn't matter what

I write here. If I were to change my

name to a single character such as B,

this would still be true.

If our string variable was empty, there

were no characters within it, that would

actually give us

false. We could use this to check to see

if somebody enters in their name or not.

If somebody types in their name, then we

type cast it to a boolean. If somebody

skips entering in their name, that would

return false. We could reprompt the user

to enter in their name again. All right,

everybody. So, that is type casting. It

is the process of converting a variable

from one data type to another. This is

especially useful with handling user

input because user input is always a

string. There may be at times where we

want to convert it to an integer, a

float or a boolean. And well everybody

that is type casting in

Python. All right everybody, in this

topic I'm going to show you how we can

accept user input in Python. We use the

input function. It's a function that

prompts the user to enter in data and it

returns the enter data as a string.

Here's an example. To accept user input,

we will call the input function. When I

run this program, we need to enter in

data to our console

window like so, then hit enter. However,

we need a

prompt. We need to tell the user what we

want them to type in. So, let's ask a

question. Our prompt will be within

quotes. Let's say, "What is your

name?" Let's try this again. What is

your name? I can type in something. Why

don't you go ahead and type in your full

name, then hit

enter. Now, with this input, we're not

quite doing anything with it. The input

function is going to return some data as

a string. We can assign it to a variable

if we would like. Let's create a

variable of name. Name equals our user

input. Then once we have our name, let's

print a message. I'll use an fstring. We

will print hello. Add a placeholder.

Then insert our name variable within

that

placeholder. Let's try

this. What is your name? Type in your

name. Hit enter. Hello. Whatever your

name is. Let's try a different name. I

will pick Spongebob. Many people are

familiar with Spongebob. Hello,

Spongebob. This time we will ask a user

how old they are. Let's assign a

variable of age equals accept some user

input. We need a prompt within

quotes. How old are you?

Once we have our age variable, let's

print I'll use an f string. You are add

a placeholder our variable

age years

old. What is your name? Type in your

name. How old are you? Let's say that

I'm

25. Hello. Whatever your name is, you

are whatever your age is. Years old.

All right. So, let's say that it's our

birthday. Before we print our age

variable, let's

say happy

birthday. Since I'm not inserting any

variables within this print statement,

this doesn't need to be an F string.

You'll want to use an F string if you

want to insert variables. Before we

display the user's

age, let's take the user's age and

increase it by one. We could say age

equals age +

one. But there's one problem with

this. Type in a

name. How old are you? Type in an

age. And we have a problem. We have a

type error. Can only concatenate

strings, not integers, to

strings. When we accept user input, we

store that input as a string. Before we

increment our age by one, we'll need to

convert it to an integer. We can't

normally use strings within arithmetic

expressions. But we can do that with

integers and floats, though. After we

accept some user input for our age

variable, we could take our age variable

and type cast it as an integer, which we

talked about in the previous lesson. So

let's say age equals our age after we

type cast it then increment it by

one. So type in your

name type in an

age and we get this message hello your

name happy birthday you are whatever

your age is years

old. So strings we can't normally use

with arithmetic expressions. We would

have to type cast it to an integer or a

float. However, we could condense some

of these steps. We're taking up an extra

line to type cast our age as an integer.

What we could do instead is that when we

accept our user input, we can enclose

the input function within a type cast to

int. And that would work the same. Type

in your

name, type in an age, and this works the

same. And it takes less lines of code

and is more readable. I would say when

we accept user input, it returns that

input as a string data type. Then we

just have to type cast it to another

data type if we need to. And in this

case for age, we do. Now, we'll go over

a couple exercises because it's

important to practice what you've

learned. In this first exercise, we're

going to calculate the area of a

rectangle. We need to prompt the user to

enter in a length and the width of a

rectangle.

So we will create a variable of length.

We will accept some user input using the

input function. What is our prompt?

Let's say enter the

length. Let's do this with width. I'll

just copy and paste what we have. Width

equals enter the

width. So we have the length and the

width. To get the area of a rectangle,

we have to multiply the length by the

width. So let's say area equals our

length variable. Now to use

multiplication you use an asterisk.

We'll discuss different arithmetic

operators in the next lesson. So we have

length time width. That is the

area. I'm going to print our area

because I need to test something. Enter

the length. Let's say five 5 in 5 cm.

Doesn't matter. Enter the width. six, we

get a type error. Can't multiply

sequence by non-int non- integer of type

string. When we accept user input, it

returns a value of the string data type.

We can't use those strings in arithmetic

expressions. We're multiplying the

length times the width. We would need to

type cast them as an integer or a float.

Since we're working with basic geometry

such as calculating the area, let's do

float. So let's type cast our user input

as a float for both length and

width. Okay, let's try this again. Let's

say 5 * 6. The area that's returned to

us is 30.

30.0. This result contains a decimal.

It's a floating point number, a

float. So when we print the area, I'll

use an f string this time. The area is

I'll add a placeholder. Display our area

variable. Let's add a unit of

measurement afterwards. I'll pick

centimeters. Now, since we're working

with areas, if we would like to

technically be accurate. So, we could

say to the power of two or we could add

a superscript. So, if you would like

superscript 2 and you're on Windows,

make sure num lock is on, hold alt, then

type on the numpad

0178. So, we have a superscript of two.

Again, it's not really necessary for

this lesson. I just think it'd be cool

to include it because then it's

technically

accurate. All right, let's say that the

length is

6.1 and the width is 7.2.

The area is

43.92 cm squared because we're working

with areas. Let's cover a second

exercise. This time we will create a

shopping cart program. Exercise two,

we're going to create a shopping cart

program. We need three variables. An

item, a price, and a quantity of those

items. We will create a variable of

item. We will accept some user input.

What item would you like to

buy? What are we trying to purchase?

We'll keep the data type of the user

input as a

string. Then we need a price. What is

the price of each item we're buying? Use

the input

function. What is the

price? A price should be a floatingoint

number. For example, we might have

dollars and cents. We need a decimal. So

let's type cast our input as a float.

Then a

quantity. We will accept some user

input. Our prompt will be how

many would you

like? Quantities. They should be whole

numbers. Let's type cast our input as an

integer. Then we will have a total.

What's the total that we have to pay?

So, let's take the price of each item.

Use an asterisk for multiply our

quantity. Then, let's do a test run.

Let's print our

total. What item would you like to buy?

Let's say a pizza. What is the price?

$10.99. How many would you like? I would

like five

pizzas. and our total is

54.95. Let's say that before we display

the total, let's print the following.

I'll use an F string. You have

bought insert a placeholder. Display our

quantity

X item or items. I'll add slash

S. Then we will print I'll use an F

string again.

Your total

is display our

total. What item would you like to buy?

I would like to buy a pizza. What is the

price?

$10.99. How many would you like? I would

like nine pizzas. They're all for me.

I'm going to eat all of

them. You have bought 9 x pizzas. Your

total is 98.91.

Let's add a unit of currency before

this. Pick unit of currency before

displaying the total. I'll pick American

dollars. I would like to buy pizza. What

is the price?

$9.99. How many would you like? I would

like a dozen pizzas.

12. You have bought 12 x pizzas. Your

total is

$119.88. All right, everybody. That is

how to accept user input in Python. And

we've covered a few exercises. In the

next topic, we're going to create a Mad

Libs game. And that is how to accept

user input in

Python. All right, everybody. In this

video, we're going to create a game of

Mad Libs. Not because we have to, but

because I want to. It would be a good

exercise for us, just so we're more

comfortable with accepting user input.

If you're not familiar with Mad Libs,

Mad Libs is a word game where you create

a story by filling in the blanks with

random words. So, we're going to create

a story template. The story is going to

be missing some components. We will fill

in those components with random words

that we type in. Here's a story that

I've written myself. Print. Use an F

string. Today, I went to a insert a

placeholder zoo.

For our placeholder, we'll insert an

adjective. We'll insert a variable named

adjective. Adjective. Adjective one.

You're going to get an English lesson

today, too. An adjective is a

description of something. So, for our

zoo, adjective one could be

expensive,

large, dirty. An adjective describe

something. We'll fill this in when we

accept user input.

For our second print statement, let's

print the

following. In an

exhibit, I saw a placeholder. We'll

include a noun. Noun one. A noun is a

person, place, or thing in English.

Maybe a gorilla. A gorilla named

Harambe, for

example. Print. Use an F string. Let's

say our noun one whatever this is we can

reuse

variables

was we will create a second adjective

adjective 2 we will be describing

whatever noun one is this person place

or thing and we will insert a verb verb

one a verb is an action such as running

or eating. Then for our last statement,

let's print I was add a

placeholder. We'll create adjective

three. Adjective 3 will describe us. Now

we're going to fill in these variables

by accepting user input. We're going to

fill in adjective

one. We'll accept user input using the

input

function. Enter an adjective.

I'm going to add a reminder that an

adjective is a description of

something. Then we need noun

one. Noun one equals

input. Enter a noun. A noun is a person,

place, or

thing. Then we have adjective two. I'll

just copy adjective one. Paste it.

Change one to

two. Then a verb. Verb one equals

input. Enter a verb. I want verb one to

be in current tense. I'll ask the user

to end the verb with ing. Enter a verb

ending with

ing. Then it's current tense. our

person, place, or thing of noun one is

currently doing something such as

eating. And then adjective three. And

I'll just copy one of these

adjectives. Adjective 3 equals input.

Enter an adjective. Okay. And then we

are ready to run this. Enter an

adjective. An adjective describes

something. I will say

suspicious or some kids like to say

sussy or sus even. I've also heard of

kids nowadays using the word skipy. Feel

free to type in whatever you would like.

It is your story after all. I'm going to

say

suspicious. Enter a noun, a person,

place, or thing. I like to poke fun at

Mark Zuckerberg. So, I'm going to say my

person is

Mark

Zuckerberg. Enter an adjective. That is

a description.

Angry. Enter a verb ending with ing. So,

it's current tense. Uh,

screeching. Enter an adjective.

Happy. Here's my story. Today I went to

a suspicious zoo in an exhibit. I saw a

Mark

Zuckerberg. Mark Zuckerberg was angry

and screeching. I was happy. That's our

game of Mad Libs. It's a word game where

you create a story by filling in the

blanks with random words. Also, post the

output of your Mad Libs game in the

comment section down below because I

really want to read them. I want to see

what you guys came up with. And well

everybody, that is a Mad Libs game using

Python. Hey everybody, in this video I'm

going to show you all of the different

math that we'll need throughout the rest

of the series. I have a lot to cover and

I'll split this video into different

sections. We'll cover some basic

arithmetic operators, built-in math

functions, a few functions from the math

module, and then a few exercises. Be

sure to look at the timestamps if you

would like to skip ahead to another

section. Let's begin with some really

easy stuff. We're going to cover some

basic arithmetic operators. Let's say we

have a variable

friends. Currently, you have zero

friends. If you need to increment a

variable by one, you could say friends,

the name of the variable equals the name

of the variable again + 1. So, the plus

sign is the addition operator. And I

think we do have a little bit of

experience with that already. So if I

were to print my variable

friends, guess what? You now have one

friend. We could also shorten this line

of

code. You could say friends plus equals

1. That would do the same thing. This is

known as an augmented assignment

operator. That will give you the same

result. I prefer to use augmented

assignment operators just because they

take less text and I think they're

easier to read. Now let's use

subtraction. Friends equals

friends minus 2. So of course minus is

the subtraction operator. Uh you have -2

friends. I guess if you were to use the

augmented assignment operator that would

be friends minus equals

2. There you still have -2 friends.

Okay. Multiplication. Let's change

friends

to how about five. Friends equals

friends time

3. You now have 15 friends. Then the

augmented assignment operator version of

this would be friends time=

3. So again you have 15 friends. Let's

cover

division. Friends equals friends divided

by

two. So we have 2.5 friends. Somebody

was cut in half. We have half a friend.

Maybe it's just their legs or torso or

something. Then the augmented assignment

operator would be

friends / equals 2. And the result is

still the same.

Now exponents friends equals friends to

the power of two. So friends is

currently five. Friends to the power of

two would be 5 * 5 which is 25.

The augmented assignment operator

version of this equation would be

friends exponent equals

2 and again friends is

25. Then we have modulus. Modulus gives

you the remainder of any division.

Suppose we have 10 friends instead of

five. I will assign a new variable

remainder. Remainder equals friends. The

percent sign is known as the modulus

operator. It will give us the remainder

of any division. If I were to divide my

group of friends by three, we will have

one remaining. I'll store the remainder

within a separate variable. We would

have a remainder of one. It's kind of

like in class when the teacher says for

everybody in the class to go into groups

of three, then there's always that one

kid that's by themselves. That's kind of

the same concept. We're dividing our

friends into groups of three. then the

modulus will give you the remainder. If

we divided our group of friends into

groups of two, well 10 divides by two

evenly, so there is no remainder. So

that is the modulus operator. It's

fairly popular to use this operator to

find if a number is even or odd because

it will divide by two evenly if that

number is even. If the remainder is one,

that means that the original number is

odd. Okay, so yeah, those are some basic

arithmetic operators. addition,

subtraction, multiplication, division,

exponentiation, then

modulus. Now what we're going to do is

cover some built-in math related

functions. Suppose we have three

variables x=

3.14, y =

4, z = 5. It doesn't matter if these are

floating point numbers or whole

integers. The first is the round

function. We have a variable named

result. I'm going to round

x. So there is a built-in round

function. After the set of parenthesis,

we can add some value or variable to be

rounded. So we will round x to the

nearest whole integer. Then print the

result. So our result is three. So

that's the round

function. With the absolute value

function, we can find the absolute value

of a number. Uh let's change y to be -4

instead of

four. We'll take result equals abs which

means absolute value of y. The absolute

value is the distance away from zero as

a whole

number. The absolute value of -4 is

4. Let's change y back to

four. There's a built-in power function.

result equals

pow. Then we'll need a base and an

exponent. What's y to the power of

3? That would be 4 * 4 * 4, which is 64.

That's the power function. You can raise

a base to a given

power. The next two are really useful.

Using the max function, we can find the

maximum value of various values. What's

the maximum value between x, y, and z?

Then I'll just need to store this value.

Uh results equals the max between x, y,

and z. Well, the maximum value is

five. Otherwise, there's

min. What's the minimum value between X,

Y, and Z? That would be

3.14. Now, in this next section, we do

have some very useful constants and

functions from the math class, but we'll

need to import the math module at the

top of our text editor. So, import math.

If you need the value of pi, you'll type

the name of the math

module.py. And I'm just going to print

this. print

math.py. The value of pi is

3.14159 and a bunch of digits that come

after. If you're working with physics, I

do know that people use the constant e a

lot. We won't be using e in this video

series, but if you ever need access to

it, just type math. E, and that will

give you e, which is 2.71 something

something something. I believe e is

known as the exponential constant. If

you need the square root of a number,

let's say result

equals math.

SQRT, we can place a variable or a value

within the square root function. Uh

let's say we have x again.

x= 9. What is the square root of x? Then

I will print whatever the result

is. The square root of 9 is three. That

is the square root

function. There's a ceiling function.

Result equals

math dot seal. Seal will always round a

floatingoint number up. Suppose x is

9.1. So 9.1 rounded up is

10. Otherwise there's floor which will

always round a number down. result

equals math.f floor. Let's change x to

9.9. 9.9 rounded down is 9. Those are

some useful math functions. Let's go

over some

exercises. Okay, this first exercise we

are going to calculate the circumference

of a circle. We'll need the help of the

math module because there's some good

functions in there. To calculate the

circumference of a circle, the formula

is 2 * * r. Let's ask a user for a

radius because that's what r is. We'll

accept some user

input. Enter the radius of a

circle. We will type cast the input as a

floatingoint

number to calculate the circumference.

Again the equation is 2 * pi. We can get

that from the math module times whatever

the radius is. And the user is going to

type that in. Then we will print

whatever the circumference

is. Print. We'll use an fstring

the

circumference

is our variable circumference.

Enter the radius of a circle. I'll enter

10, actually

10.5. Their circumference is

65.97. If you want to round and truncate

some of these numbers, we can use the

round function. Round

circumference, then round to a given

decimal place. I'll round to two

digits. Again, 10.5 rounded is

65.97. You could add a unit of

measurement, too. Let's say centimeters

10.5 is

65.97 cm. All right, that is the first

exercise. For this next exercise, let's

calculate the area of a circle. We'll

import the math

module. We'll ask for a radius. Much

like before, radius equals

input. Enter the radius of a circle.

We'll cast our input as a floatingoint

number. The equation for the area of a

circle

is

pi time radius squared. We could easily

use the built-in power function to raise

our radius to the power of two. Then we

will display the area. print. I'm using

an F string. The

area of the circle

is our area to some unit of measurement.

Let's say centime

squared. Enter the radius of a circle

10.5. The area of the circle is

346.36. But I would like to round this

number to two decimal places.

I'll use that round

function and I'll place area and the

number of digits to round to within this

function. Let's try that again.

10.5. The area of the circle is

346.36 cm squared. That is the second

exercise. For this last program, we're

going to find the hypotenuse of a right

triangle. The formula to calculate the

hypotenuse of a right angle triangle is

C equ= the square of A^2 + B^2.

We'll begin by importing the math

module. We'll ask the user for the

lengths of side A and

B. A

equals

input. Enter side

A. We'll cast the input as a

floatingoint

number. We'll do the same thing with

side B.

B

equals enter side

B. Now this part's going to be

confusing. We'll calculate C. We'll need

A^2 + B ^ 2. We'll take A to the^ of 2

plus B to the^ of

2. Then we'll need the square root of

all of this. Whatever the result is, I

will surround this equation with math.

Square root and that should give us our

answer. Let's

print using an F

string. Side C

equals whatever C

is. So, enter side A three. Side B will

be four. side C is five. All right,

everybody. So, that was everything

related to some arithmetic operators and

math related functions in Python. And in

the next video, we're going to cover a

few things involving string

[Music]

formatting. Hey everybody, in this topic

I'm going to explain if statements. An

if statement is used to do some code

only if some condition we set is true.

Else we could do something else. It's a

basic form of decision-m. If it's true,

we do something. If it's not true, we

don't do it. Let's ask a user for their

age. Age equals

input. Enter your age. I will type cast

the input as an

integer. Depending on what the user's

age is, we can do one of a few things.

Let's pretend that the user would like

to sign up for a credit card, but in

order to do so, their age needs to be

greater than or equal to 18. Well, we

can check that. To use an if statement,

type if, then some condition. What would

we like to check? Let's check to see if

the user's age is greater than or equal

to 18. Then add a colon, then hit enter.

Any code underneath the if statement

should be indented. Make sure to pay

attention to that because that's easy to

miss. If the user's age is greater than

or equal to 18, let's print you are now

signed

up. If I were to run this code, I'll

type in my age. I'll type 21. Hit enter.

This statement is true. Therefore, we

will execute any code found within the

if statement. You are now signed up.

What if this condition was not

true? Let's say my age is 13. Well,

nothing happens. If the condition we

check is instead false, we skip over

this code. If you need to take a

different course of action, you could

add an else

statement. If this is true, do this.

Else, we can do something

else. Let's print a different

message. You must be 18 plus to sign

up. I'll type in my age again. I'll say

that I'm 13. Hit enter. You must be 18

plus to sign up. That's basically an if

statement. Do some code only if some

condition is true. Else you can do

something else entirely. It's a basic

form of decisionm. The else statement is

kind of like a last resort. We can check

more than one condition before reaching

the else statement. We can add an else

if statement which we just shortened to

e l i if meaning else if. else if let's

check if age is less than

zero then we'll print a different

message you haven't been born

yet. Now if I run this code I'll say

that my age is negative one.

This condition is false. We skip this

code. This condition is true. Therefore,

we will execute this code and we skip

the else statement. You haven't been

born yet. Let's add another else if

statement. You can add as many else if

statements as you want. Let's check to

see if somebody's age is greater than or

equal to 100. We'll print a different

message.

Let's print you are too old to sign

up. If I were to say my age is 111 years

old, well, it states you are now signed

up. The reason that we didn't reach this

part of our else if statement. That's

because this condition is still

technically true. You do need to pay

attention to your order of if and else

if statements. If I want to be sure that

nobody over 100 is signing up, I should

probably move this to the

beginning. If age is greater than or

equal to 100, then else if age is

greater than or equal to 18, we'll do

something

else. Enter your age. I am 111 years

old. You are too old to sign up. So

those are if statements. If some

condition is true, do something. else if

you can check something else. If no

above conditions are true, you could do

something else entirely. It's kind of

like the default. Here's another

example. We'll ask a user if they would

like some food. Response equals

input. Would you like

food? We'll have the user type in Y for

yes or N for no.

If our

response now to check to see if two

values are equal, you would use double

equals. If the response is equal to y,

then we will

print have some

food. The doubles equal sign is the

comparison operator. It will check to

see if two values are equal. You don't

want one equals because that's the

assignment operator. Python in this case

thinks we're attempting to assign the

character y to response. So for

comparisons use double

equals else we can

print no food for

you. So would you like food? I'll type

y. Have some

food. Let's try it again. I'll type no

and for no. No food for

you. Here's a third example. We'll have

a user type in their name. Name equals

input. Enter your

name. If our name is equal to an empty

string, that means they didn't type in

anything. So, let's yell at the user.

You did not type in your

name. Else we will print using an

fstring hello whatever the name

is. Enter your name. I'm just going to

hit enter. You did not type in your

name. Let's run this again. I'll type in

my

name. And we have executed the else

statement this time. Hello

bro. So one important thing that you

should know is the use of booleans with

if statements. Suppose we have some

boolean variable named for sale. I'll

set this to be true. Now using an if

statement you can just use the boolean

variable in place of a condition because

a condition would evaluate to be true or

false.

We could just say if for sale if that's

true then let's

print this item is for

sale. Else we will

print. This item is not for sale. For

sale is set to be true. This item is for

sale.

If this variable were

false, well then the item is not for

sale. Let's try a different variable.

How about

online?

If

online, the user is online. Else the

user is

offline. So the user is

offline. I'll change the boolean to

true. the user is

online. So with if statements, you can

either write a condition or you could

use a

boolean. All right, everybody. So those

are if statements. Do some code only if

some condition is true. Else you can do

something else. It's a basic form of

decision-m and those are if statements

in

Python. Hey everybody, this is a remake

of my Python calculator program for

absolute beginners. All you need to know

to complete this exercise is just if

statements and how they work. So let's

get started. For this exercise, a user

is going to select an arithmetic

operator. Operator equals input. We will

ask the user to enter an

operator. This will be plus for

addition, minus for subtraction,

asterisk for multiplication, and a

forward slash for division. You could

enter more than this, but I don't want

to make this exercise too complicated.

We will create a variable of num one to

contain our first number. Let's say we

would like to add two numbers together.

What is the first number going to

be? Enter the first

number. And let's do this with the

second

number. Num two. Enter the second

number. Let me show you something.

I'm going to add num one and num two

together. Num one plus num two. We'll do

a test

run. Enter an operator. I would like to

use addition. Enter the first number 10

and 11. Well, the result is

1,1. When we accept user input, they are

string data types. What we've ended up

doing is string concatenation. We've

concatenated the string of 11 to 10.

That's why we ended up with 1,1. We'll

have to convert these two strings to be

floating point numbers by type casting

them as a

float. So enclose your input functions

with a type cast a float. And now we

should be able to add those two numbers

together. So let's add 10 and 11 and we

get 21.0. 0. Depending on the operator

that the user selects, we'll use some if

statements to determine that. We will

check if our operator variable is equal

to a character of

plus. And for now, I'll write pass as a

placeholder. We'll get back to this

later. Else if our

operator is equal to minus, we will use

subtraction. And for now, I'll write

pass.

Else if operator is equal to an asterisk

for multiplication, we will

multiply. Else if our operator is equal

to a forward slash for division, we will

divide. If our operator is addition,

let's create a variable of

result. Result equals num 1 + num

2. For

subtraction, it's going to be num 1

minus num

2. Multiplication would be num 1 * num

2. Then division would be num 1 / num 2.

Then we just have to print the result.

Print our

result. Be sure to do this with each of

the else if statements as

well. And let's see what we have.

Let's add 5.5 +

6.9. That gives us

12.4. Let's

subtract

420 minus

0.69. That gives us

419.31. Let's test

multiplication. Multiply

3.14 times

3.14, which gives us 9.8596.

8596. Then

division. Let's

divide 69 by

13. And that gives us a really long

number. So you could round a number if

you would like. We would enclose our

result within the round

function. And we'll just update each of

these print

statements. This will round to the

nearest whole integer. So let's divide

420 by

13. Let's say that we would like three

digits after the decimal. Within the

round function, we could add comma 3 for

three decimal

places. Enter operator. Let's use

division. Divide 420 by

69. So that gives me

6.087. So, we can round to a given digit

after a decimal. In this case, three

places. What if somebody types in an

operator that doesn't exist, like the

word

pizza? Then I will divide two

numbers. Well, let's add an else

statement. If somebody selects some

input that is invalid, let's let them

know. I'll use an fring.

Let's say that the operator that the

user has

selected is not valid. And let's try

this again. Enter an operator pizza.

Enter the first number 420 and

69. Pizza is not valid. Let's say is not

a valid operator instead. That makes

more

sense. Pizza will be my operator.

First number is 420. Second number is

69. Pizza is not a valid

operator. All right everybody. So that

is a very simple Python calculator

program you can make as a

beginner. Hey there, it's me again. In

today's topic, we're going to create a

weight converter program in Python. This

is an exercise that will follow up the

lesson on if statements. We'll convert

pounds to kilog or kilog to pound. The

user is going to decide. We will begin

by creating a weight variable. We will

assign some user

input. Enter your

weight. We will convert this input into

a floatingoint

number. So add that cast. Then we will

ask for a unit. Is this weight in

kilogram or

pounds?

Input kilogram

or pounds.

We want the user to type in either K for

kilogram or L for pounds. And these are

capital letters, by the

way. Using an if statement, let's first

check to see if our unit is equal to a

capital K. That means the current weight

is in kilogram. We need to convert that

weight to pounds.

Let's reassign weight equal

to our weight

times

2.205. Else if unit is equal to L, we

need to convert to

kilogram. Weight equals weight divided

by

2.205. Else the user did not type in

something that was valid. Let's

print using an

fstring

unit was not

valid. At the end of our program, we

will print the new weight. I'll use an

fstring. Your weight

is our new weight after it's reassigned.

Now, we need a unit of measurement. This

is what I'm thinking we'll do within our

if and else if statements. Let's

reassign our unit. We're reassigning

unit to be lbs for

pounds. Else if unit equals kgs for

kilogram in our results, we will display

our new unit. Let's take a look. Enter

your weight. Actually, I'm just going to

make one change. I'm going to add colon

space there. That's much better.

Enter your

weight. Let's say I'm 180 lb. This is in

pounds. I'll type capital L. Your weight

in kilog is

81.63. I think I'm going to round this.

I will enclose the weight variable

within a round

function. We will round to one decimal

place. Let's try this again. Enter your

weight. Maybe I'm 81

kg. I'll type k for kilogram.

Your weight is 178.6 lb. Let's make sure

that this else statement works, too.

Enter your

weight. 180

pizzas. Pizzas was not valid. So, we're

still displaying our output. We would

want to avoid that if somebody doesn't

type in a valid unit. So, let's cut this

line. Then, paste each within the if and

else if

statements. When we exit the else

statement, we're not printing the

output. So, let's make sure that this

works. Enter your weight. I am 180

pizzas. Pizza was not

valid. All right, everybody. Well, that

is a weight converter program in Python.

I thought this would be a helpful

exercise now that we have finished the

section on if statements. And yeah, that

is a weight converter program in Python.

Hey everybody. In this topic, we're

going to create a temperature conversion

program as an exercise. We'll begin by

asking what the current unit of

measurement is. Unit

equals will accept some user

input. Is this

temperature

in

Celsius or Fahrenheit?

C

slashF then we will ask for the

temperature. I'll store the temperature

in a variable named temp meaning

temperature. temp equals

input enter

the

temperature. Then we should cast our

user input as a floatingoint

number. If unit is equal to

C, I'll fill this in momentarily. I'm

just going to write pass as a

placeholder. Else if unit is equal to F,

we will do something

else. Else, let's print something. Just

an error message of some sort using an F

string.

unit

is an invalid unit of

measurement. Let's test this else

statement. Is the temperature in Celsius

or Fahrenheit? What if I were to type K

for Kelvin? I'll make up some

temperature like 100. K is an invalid

unit of measurement. All right, we know

the else statement works. Let's convert

Fahrenheit to Celsius using this

formula. We will take our

temperature

equals 9 * our

temp /

5 +

32. I'll take all of this and use the

round function. We'll round to one

decimal

place. Then we will print the current

temperature in

Fahrenheit. I'll use an F

string. The

Temperature

in Fahrenheit

is our temp

variable degrees

Fahrenheit. Let's test this if

statement. Is the temperature in Celsius

or Fahrenheit? It is currently in

Celsius. What is 33° in Celsius

converted to

Fahrenheit? The temperature in

Fahrenheit is 91.4°.

All right, so this section is working.

Let's work on the else statement. Else,

if our unit is currently in Fahrenheit,

we'll convert to

Celsius. That formula is temp

equals our temperature minus 32

* 5 /

9. Then I will round the result to one

decimal place.

Then we'll print the temperature in

Celsius. The temperature in Celsius is

temp° C for

Celsius. Is the temperature in Celsius

or Fahrenheit? It is currently in

Fahrenheit. Enter the temperature.

91.4. The temperature in Celsius is

33.0°.

Well everybody that is a simple

temperature conversion program in

Python. All right people, we're talking

about logical operators today. Logical

operators allow us to evaluate multiple

conditions. We can link them together.

There's three we'll discuss or and not.

We'll begin with or. With or we can

check more than one condition. If at

least one of those conditions is true,

then the entire statement is true.

Here's an example. Let's say we have an

outdoor event. And I will create two

variables. One temp, meaning

temperature. Let's say that this is in

Celsius, 25° C. Pick Fahrenheit if you

would like. And I will create a boolean

variable of is raining. I will set that

to be false. It is currently not

raining. If the temperature is too hot,

too cold, or it's raining, then I will

cancel this outdoor event. We'll write

an if statement to check that. If our

temp short for temperature is greater

than let's say 35 35° C then I'll use

the or logical operator or if our temp

is less than

zero or if is raining is

true. If one of these conditions is

true, we're going to cancel our outdoor

event. So let's print the following. The

outdoor event is

cancelled. Else we will print something

else. The outdoor

event is still

scheduled. The temperature is reasonable

and is raining is false. It's not

raining. So we print the else clause.

The outdoor event is still scheduled.

What if the temperature was really hot,

like

36°? Well, the outdoor event is

cancelled. What if it's cold?

-5°. The outdoor event is canled. This

condition was true. Therefore, we

execute the if statement. Or what if the

temperature is reasonable, but it's

raining? Is raining is true.

Well, then the outdoor event is still

canled. So with the or logical operator,

at least one of these conditions needs

to be true. If one of these conditions

is true, you could consider the entire

statement

true. Now let's cover and. With and, we

can link two conditions together. Both

conditions must be true in order for

that entire statement to be true. So

again let's say we have temp short for

temperature and we have a boolean

variable of is sunny. I will set that to

be

true. We will check if our temp is

greater than or equal to

28° and is it sunny. Is

sunny if it's hot and if it's sunny. If

this is true, let's print the

following. It is hot

outside. For fun, I'm going to add an

emoji, but you don't have to. I just

think it's more entertaining that way,

but you do you. And I will

print it is

sunny. Sometimes these emojis are

formatted differently. I'm just going to

copy it from somewhere else. That's

better. Currently, the temperature is 25

25° C and it's sunny. This condition was

false, but this one is true. With the

and logical operator, both conditions

must be true in order for us to execute

this block of code. If our temperature

was

30°, well, then both conditions are

true. It is hot outside and it is sunny.

Let's write a few more. Let's add else

if. Else if the temp is less than or

equal to

zero and is

sunny. We will print something

else. It is cold

outside. I'll change the

emoji and it is

sunny. Let's set the temperature to

be5°.

It is cold outside and it is

sunny. Both these conditions are true.

So we do this

instead. You can link as many conditions

together as you would like. Let's see if

our temperature is within a certain

range. Else if temp is less than 28 and

our temp is greater than zero and is

sunny. to check to see if something is

within a certain range. There is a

shortcut too. PyCharm is recommending

this. We can simplify chain

comparisons. So this effectively does

the same thing. If 28 is greater than

our temp and our temp is greater than

zero and it's sunny, then we will print

it is warm outside rather than

hot. and it's still sunny. So, let's say

our temperature is 20° C and it's

sunny. It is warm outside and it is

sunny. Now, we have the not logical

operator. It inverts the condition. We

are checking to see if something is

either not false or not true. So, let's

check to see if it's not sunny. Really,

I'll just copy what we have and paste

it.

else if not is

sunny then that means it's

cloudy and let's use a cloud

emoji. So basically not does the

opposite of what you're looking for. We

are checking if not is sunny. Is sunny

is false. Then this condition is true.

Okay. Let's say our temp is

28. Is sunny is now

false. It is hot outside. It is cloudy.

What if our temperature was

zero? It is cold outside. It is cloudy.

What if the temperature was reasonable

like 20°?

It is warm outside. It is cloudy. So not

it inverts the condition. If it's true,

it's now false. If it's false, it's now

true. All right, everybody. So those are

logical operators. They allow us to

evaluate multiple conditions. With or,

at least one condition must be true.

With and, both conditions must be true.

And not. Not does the opposite. It

inverts the condition. We check if

something is not false or not true. And

well everybody, those are logical

operators in

Python. Hey everybody. So today I got to

explain conditional expressions in

Python. A conditional expression is a

oneline shortcut for using an if else

statement. If you're familiar with other

programming languages, this is also

known as the trinary operator. It

behaves similarly. Using conditional

expressions, we can print or assign one

of two values based on a condition.

Here's the formula. Return X if our

condition is true. Else return Y. Here's

a basic example. We will create a

variable for number just num. Let's say

our number is five. I'm going to print.

Then within our print statement, I will

write a conditional expression following

this formula. I'll just copy and paste

it. Let's check to see if our number is

positive. Let's print the text positive

if our condition. What are we checking?

Let's check to see if num is greater

than zero. That means it's positive. If

this condition is false, we will instead

print whatever comes after else.

Else negative number is five, that will

print positive. If our number was neg 5,

well, this condition would be false. We

would instead print negative. Let's go

over another. Let's check to see if our

number is even or odd. Let's set num to

be

six. This time I will assign the result

to a variable. Our result

equals take our

formula. Let's

assign even

if our

num modulus 2 is our number divisible by

two. Does that equal zero? Else return

odd. Then let's print our

result. R

result number is six that is even. If

it's five then it's odd.

assign even if our number is divisible

by two. Else return

odd. Let's create variables A and

B. A will equal 6. B will equal

7. Let's create a variable of max num

equals. Follow our formula again.

return variable a if a is greater than b

else return b between a and b which is

the maximum number that would be b of

seven let's find the minimum this

time min num a if a is less than b else

return b the minimum number between 6

and 7 is

This time we'll take an age. Age equals

25. We will create a variable of status

equals. Use our formula

again. Return a string of adult. If our

age is greater than or equal to 18. Else

return a string of child. Then we will

print our status. Our age is 25. that's

greater than or equal to 18, we will

print adult. If our age was 13, then we

are a child. We will instead return

child. Let's work with the

temperature. Temperature equals 30°

C. So that's

hot. Let's create a variable of weather.

assign a string of hot if our

temperature is greater than 20. Else we

will return a string of cold. What's the

weather outside today? Based on the

temperature it is hot. If our

temperature was

20 then the weather is cold. Okay, last

example. We will work with a user role.

I will set this to be admin.

We will define a variable of access

level

equals again follow our

formula return the text of full access

if our condition of user ro is equal to

a string of admin else we will

return limited

access. Our user role is an admin. Let's

print our access level and we have full

access. But what if we were a

guest? Well, then we have limited

access. All right, everybody. Those are

conditional expressions. They're a

oneline shortcut for the if else

statement. It's similar to the turnary

operator in other programming languages.

Using conditional expressions, we can

print or assign one of two values. based

on a condition, you follow the formula

of return x if our condition is true,

else return y if it's false. And well

everybody, those are a few examples of

conditional expressions in

Python. Hey everybody, in this topic I'm

going to cover a few useful string

methods that you may be interested in.

Then at the end of this video, we will

work on an exercise where we will

validate some user input. As we know a

string is just a series of characters.

Let's ask a user for their full name.

Name equals

input enter your full

name. The first method I'll show you

well technically this is a function. The

length function will give us the length

of a string. How many characters is it?

we will find the length of our variable

name after the user types in some input.

This function returns an integer. I'll

store that result within a variable. Uh

let's just say result. Then I will print

whatever the result

is. Why don't you go ahead and type in

your full

name. The length of this string in my

example is eight characters. That does

include spaces too. 1 2 3 4 5 6 7 8. If

you ever need the length of a string,

there is the length function. Let's move

on. If we were to type our variable name

followed by a dot, we have access to a

whole bunch of different methods. We

have the find method. The find method

will return the first occurrence of a

given character, the position. Let's

find any spaces.

I'll store the result within a variable

named

result. I will type in my full

name. The first occurrence of a space,

that's what we set, is at position

three. When working with indexes, we

always begin with zero. This first

character would have an index of zero,

then 1 2 3. That's why the find method

returned three in place of four. Let's

find the first occurrence of a capital

B. See, it's zero. How about

O? For me, that would be two. So

remember, it's always the first

occurrence. If you need the last

occurrence, there is a different

method, which is R find. R meaning

reverse. We will find the last

occurrence of an

O that has a position of five. 0 1 2 3 4

5. If Python isn't able to locate a

given character, it will return negative

1. Let's find any I don't know uh

Q's. Python could not find any lowercase

Q's. The rfind method will return

negative 1 if there are no results. We

can capitalize the first letter in a

string by using the capitalize function.

Name dot

capitalize. This method will return a

string. I will reassign that to

name. Then we will print our name

capitalized.

I'll be sure to type in my name, all

lowercase. Since this is all one string,

only the first letter is capitalized,

even though I'm including a first and

last name. The upper method will take

all of the characters in a string. Then

make them all

uppercase. Follow your variable that

contains a string followed

byupper. Then I will reassign the result

to my name variable to overwrite it.

Enter your full

name. All of the letters are now

uppercase. There is also lower to make

all of the characters

lowerase. Name equals name dot

lower. Yep. All the characters are

lowercase. Now the is digit method will

return either true or false. If a string

contains only digits, the result is a

boolean, true or false. I'll store that

within a variable named result, then

print

result. So if I were to type in my full

name, is digit returns false. There are

not only digits within that string. If

my string was some combination of

alphabetical characters and numbers,

this method will still return false. It

only returns true if my string only

contains

digits. I'll just type in 1 2 3. See

that's true. That is the isdigit

method. Otherwise, we have is alpha name

is

alpha. The is alpha method will return a

boolean true or false depending if a

string contains only alphabetical

characters. I'll type in my full name.

So, the reason that this came up false

is because my full name contains a

space, which is not an alphabetical

character. If I typed in my full name

excluding any spaces, this would now be

true. Is alpha would also return false

if my name contained any sort of digits.

Bro 1 2 3. And that is also

false. That is the is alpha method.

Now let's ask for a phone

number. Phone number equals

input. Enter your phone

number. With the phone number, they

typically contain dashes. Let's count

how many dashes are going to be in

somebody's phone

number. Phone

number

dot count method. Let's count the amount

of dashes. So, place a character within

the count method. This method will

return an integer. Let's store that

within a variable. Result equals phone

number.

Method. So, type in some phone

number. 1-23

4-56-

8901. We have three dashes within the

string. 1 2 3. That is the count method.

We can count how many characters are

within a

string. We also have the replace method.

Honestly, the replace method is probably

one of the most useful methods of

strings. We can replace any occurrence

with one character with another.

Replace. Let's replace any

dashes with maybe a space. This method

will return a new string. I'm going to

reassign this to our phone number

variable.

Then print the phone

number. Enter your phone number.

1-234-567-8901. So, here's my new phone

number, but we've replaced all of the

dashes with spaces. Even better yet, we

could eliminate all the dashes

completely by replacing the dashes or

another character with an empty string.

1-234-567-8901. Here's our new phone

number without any dashes. We've

replaced all dashes with an empty

string, no characters. If you would like

a comprehensive list of all of the

string methods available to you, you can

use the help function. Type in the data

type string string. Then I will print

whatever the result

is.

Here's a bunch of methods you might be

interested in in the future. Capitalize,

case, fold, center, count, encode, ends

with, just to name a few. All right,

everybody. Here's an exercise for you.

We will validate some user input. We

would like a user to enter in a valid

username. However, there's a couple of

rules. The username can be no more than

12 characters long. The username must

not contain any spaces and the username

must not contain any

digits. Let's assign a variable named

username equals

input. Enter a user

name. First, let's check to see if our

user input is more than 12 characters

long. We can do that using the length

function. we will find the length of our

username. The length function returns an

integer. Let's check to see if the

length of our username is greater than

12 characters. If it is, we'll print a

message. Your

username can't be more than 12

characters.

else we will print using an

fstring welcome whatever our username

variable

is. Let's try it. I'll type in my first

name, last name, then add a whole bunch

of characters

afterwards. Your username can't be more

than 12

characters. Let's type in something

that's under 12

characters. Yep. And that appears to

work. Okay, so we have accomplished task

number one. Our username can't be more

than 12 characters. Next, our username

must not contain any

spaces. We can use the find method of a

string.

Username.find. We will find any spaces.

That's a character. If no spaces are

found, this method will return -1.

Using an else if

statement I'll add not if the find

method of

username

equals1. If the result is not -1 meaning

we found a space we will print your

username can't contain

spaces. I'll type in my first and last

name. You might need to think of

something that's underneath 12

characters. Your username can't contain

spaces. So, we have accomplished rule

number two. Three. Username must not

contain

digits. We can use the is alpha method

of

strings. The is alpha method returns a

boolean if a string only contains

alphabetical characters. So, let's copy

that. I'll add another else if statement

not username is

alpha. Then we will

print your

username

can't contain numbers. I guess

technically is alpha would check for

spaces too, but I'd rather have that be

handled within a different if statement.

All right, I'll type in a username. I'll

include some

digits. Your username can't contain

numbers. All right, I think we've

accomplished this. Let me make up a

username following these three rules.

Yep, it seems to check out. All right,

everybody. And that is a few useful

string methods that you may be

interested

in. Hey everybody. In this topic, I'm

going to explain string indexing.

Indexing allows us to access the

elements of a sequence using a set of

square brackets, also known as the

indexing operator. Using this set of

square brackets, following a string,

there are up to three fields that we can

fill in. We can access a starting point

in the string, an ending point, and a

step. Here's an example. Suppose we have

a credit card number.

credit number equals and I'll just make

up some number 1 2 3

4-5678-9012 dash 3456. Good enough. If I

need the first character within the

string, I can type the name of my string

variable followed by the indexing

operator which is a set of square

brackets. The first position has an

index of zero. Computers always start

with zero. So that's why the first index

is zero. Then I'm going to go ahead and

print this. Print credit card number at

index of

zero. That would be one. If I were to

change the index to be one, 0 1, that

should be two. Index

two would technically be

three. Then four is the dash within our

string. As you can see here with the

indexing operator, there's up to three

fields that we can fill in a start, end,

and a step. If you have just one field

listed without any colons, it's assumed

you're filling in the starting position.

So now, what if you would like the first

four digits of the

string? Well, we would type the name of

our string

variable indexing operator.

We'll need a starting

index colon then an ending index. The

first four digits would be zero colon 4.

Then I will print

this. And I'm just going to turn this

first line into a

comment. Yeah, there we go. We have the

first four digits of our credit card

number. 1 2 3 4. Just so you know, with

the ending index, this index is

exclusive. This first number would be

zero 1 2 3 4. So we did not include that

dash within the number. The starting

index is inclusive. The ending index is

exclusive. So you can omit the zero in

the beginning. You could just say colon

4. Python assumes the starting position

will be the beginning of the string. So

that would work too. Let's get the next

set of digits.

5678 credit number indexing operator.

Let's find where the starting index

would be. 0 1 2 3 4 5 5 colon 6 7 8

9. Then we will print whatever is

here. The next set of digits is 5 6 7 8.

Maybe we need the last 12 digits. Well,

what we could do in that case, we will

take our string variable credit

number. Set the starting index to be

let's see 0 1 2 3 4

5 5 colon. If you need everything up to

the end of the string, you don't need to

list an ending index. Just be sure to

add that colon. Python then assumes you

need everything up to the end of the

string. So, I will print whatever we

have. Then we should have everything

besides the first four digits. Yep. 5 6

7 8 9 0 1 2 3 4 5

6. You could also use a negative

index. Credit number. If you need the

last character in a string, you would

set the index to be -1. Then I will

print

this. Print credit number at index of

-1. That would be

six. -2 is

five. -3 is

four. -4 is three. And then5 would be

that dash right here. Yeah, you can use

negative indexes too. Let's talk about

step. Using the step field, we can

access the characters in a string by a

given step. We can count by twos or we

can count by threes. So here's an

example. So let's take our credit

number. If we're not filling in these

starting or ending fields, but we need a

step, we would need two colons. Then

Python is assuming everything from the

beginning of the string to the end. Then

our step will be

two. This will print every second

character within our

string. Yeah, here we are. We have 1 3

dash 6 8 9 1 so on and so

forth. If I were to change the step to

three, we would count every third

character beginning with 1

4 6

dash 1

36. All right, here's a practical

example. Let's create a program to get

the last four digits of a credit card

number. I'm going to assign this to a

new

variable.

Last digits equals our credit

number indexing operator. So, we need

the last four digits. Where would the

starting index begin? Well, we could use

negative indexing. This last digit is

-1, -2, -3,4. We will begin at

-4 colon. We can omit the ending index.

Python assumes we need the rest of the

string. Then really, that's all we need.

So, let's

print. I'll use an

fstring. Uh maybe some x's. Maybe we're

hiding somebody's credit card number

except the last four

digits. Okay. then variable

last

digits. All right. And here's our credit

card number where only the last four

digits are visible. Hey, you know what?

Let's add one more exercise. Let's

reverse the characters in the string.

I'm going to reassign credit

number equals credit

number. If we need the entire string, we

don't necessarily need a starting index

or an ending index. But for the step,

this will be negative. Negative -1 will

reverse a string. Then let's print

whatever our new credit card number

is. Print credit

number. And yeah, there is our credit

number backwards. To reverse a string,

you set the step to be -1. So yeah,

everybody, that is string indexing in

Python. We can access elements of a

sequence using the indexing operator

which is a set of straight brackets. You

can list a starting position, ending

position and even a step if you need to

skip over characters. But yeah, that is

string indexing in

Python. Hey everybody, in this topic I'm

going to explain format specifiers.

Format specifiers when used in the

context of an string, they allow us to

format a value based on what flags are

inserted. Following your value, you

would type a colon and then some flags.

Depending on what flags you insert, it

will format your output a certain way.

You could add decimal point precision,

allocate space, zero pad values, left

justify, right justify, center align,

all sorts of things.

Let's have some practice. I'll create

three prices. Price

one, price

two, price three. Price one will be

3.14159. These values aren't in dollars

and cents yet, but they will

be. Price two will be

987.65. As you can see, I'm just making

up numbers here. Price three is

12.34. Let's display our prices using

some

fstrings. Price one is placeholder price

1. Then we will do this for price two

and price three. Price two is price two.

Price three is price three. Within our

placeholder following the value, we can

add a colon. Then some flags. Those

flags are the format specifiers. They

will format our value a particular way

depending on what we insert after the

colon. To add decimal point precision,

you would type after the colon dot then

the amount of decimals to be displayed

maybe two then f meaning floatingoint

number. Let's do that with price two and

price three

colon.2f. Price one is now 3.14. Price 2

is987.65. Price three is

12.34. I think I'm going to add some

dollar signs before the

placeholder. Yeah, that's much better.

For less precision, maybe one decimal

place, you can change the two to a one.

So.1

F. Each number only displays one

decimal. 0.1

6.3 whereas in 3F would display three

decimal

places.142

650.340 even though price 2 and price 3

only have two decimal places in the

original numbers we will concatenate

some additional zeros to allocate space

to display a value after the colon add

some number some number for that many

spaces how about

10. Each value now has a total of 10

spaces to display the output. 1 2 3 4 5

6 7 8 9

10. If you were to preede a number with

zero, well, these numbers would be zero

padded. Each number is now zero padded.

To left justify a value, you would use a

left angle

bracket. All these numbers are now left

justified. Then we have all of the space

after. They're all uniform. Right

justify would be a right angle

bracket. And I believe that's the

default. Center align I believe is the

carrot symbol.

Yep, our numbers are now

centered. If you have any positive

values and you would like to display a

plus sign, just use

plus. Any positive number is preceded

with a plus sign. Any negative number is

preceded with the negative sign. Or you

could use a space for any positive

numbers. So, colon space

These numbers are lined up evenly even

though we have a negative number in

here. There is a thousand separator

which is a

comma. We should probably increase the

value of our

prices.

3,00

9,870

1,200. Each thousand's place is now

separated with a comma. We could also

mix and match flags. I would like a

thousand separator along with decimal

point precision of two decimal

places. And why not? I will preede each

number with a plus sign if it's

positive. Yep, here we are. So based on

what you're looking for, you can add

some combination of flags. So yeah,

those are format specifiers. everybody.

Within your

placeholder, insert your value, a colon,

then certain flags based on what you're

looking for

exactly. But yeah, those are just a few

format specifiers in

Python. Hey everybody, in this topic,

I'm going to explain while loops. A

while loop will execute some code while

some condition remains true. Here's an

example. We'll use an if statement

first. We will ask a user for their

name. name equals

input. Enter your

name. If our name is equal to an empty

string, that means the user didn't type

in anything. Let's print a

message. You did not enter your name.

Else, we will

print using an string,

hello, our user's name.

If I were to skip this

prompt, we would execute this if

statement. Then we continue with the

rest of the program. What if I would

like to continually prompt the user to

type in their name? We can't continue

until they type in something. Well, we

could replace this if statement with a

while

loop. While this condition is true,

continue to execute this code. within

the while loop. I'm going to reprompt

the user to type in a

name. Then if we were to exit the while

loop, then we will print hello. Whatever

your name is. So let's run this. Enter

your name. I'm going to hit enter. You

did not enter your name. Enter your

name. No. No. No. Okay, I give up. I'll

type in my first name. Hit enter. Hello.

Whatever your first name is. while this

condition remains true, execute this

code potentially forever until this

condition is no longer true. So that's

one of the main benefits of a while

loop. If it's not true, then you exit

out of the while loop. And that's why

we're able to continue then print our

name. Hello name. You do want some way

to escape out of the while loop.

Otherwise, you'll run into what's known

as an infinite loop. So let's say while

name is equal to an empty string, we

will print you did not enter your

name. So I'm going to hit enter. So we

are stuck in an infinite loop. We can't

actually escape this loop. We didn't

give ourselves an exit

strategy. That's why previously we

reprompted the user to type in

something. We're giving them a chance to

escape. In a way, it kind of works like

an if statement, but instead of

executing some code once, it's

potentially infinite. Here's another

example. This time, let's ask for a

user's age. Age equals, and I will

convert the input to an

integer. Enter your

age. We'll need the user to type in a

positive number. While age is less than

zero, let's print a message to let the

user know that they can't do that.

age can't be negative. Then we need some

strategy to escape. Let's reprompt the

user to enter in their

age. Once they type in something that's

valid, we can escape out of the while

loop. So let's print using an fstring

you

are age years

old. So enter your age. I'm going to say

negative one. Age can't be negative.

-21 million. Okay, I give up. How about

21? You are 21 years old. So, that was

another example. While our age variable

is less than zero, repeat this code

forever. Let's go over example

three. I'm going to introduce some

logical operators. We will have the user

type in a food they like. food equals

input enter a food you like. But in

order to escape, they need to press Q to

quit. While food is equal to the letter

Q, continue this while loop. However,

I'm going to make one change. We want to

exit the while loop when they press Q.

So you could say while not food equals

Q. So within this while loop, let's

print the food that they stated that

they like. I'll use an F string. You

like your variable food. Then we will

prompt the user to enter in another food

that they like. Enter another food you

like. Q to

quit. Then once we escape the while

loop, we will print just

buy. Okay. Okay. Enter a food you like.

Q to quit. I like pizza. You like pizza.

I like sushi. You like sushi. I like

ramen. You like ramen. Okay, this

program is kind of lame. So, I'm going

to press Q to quit. And we escape the

wild loop. We have printed by. So, you

could do something while something is

not true by using the not logical

operator. All right, last example.

Example four. We will use the or logical

operator. We'll ask a user to type in a

number between 1 and

10. Let's say num equals

input enter a number between 1 through

10. Then I will type cast the input as

an integer.

While our number is less than one or our

number is greater than 10, let's

reprompt the user. Let's print using an

fstring our variable

num is not valid. Then we will reprompt

the

user. Enter a number between 1 and

10. Once we escape the while loop, then

we will print our number using an fring.

Your number is our variable

num. Enter a number between 1 through

10. 0. Zero is not valid. Negative

1 100. Nope. Uh five. Your number is

five. That's an example of how you can

add logical operators to wild loops.

while this condition is true or this

condition is true, execute this code

forever. All right, everybody. So, those

are while loops. A while loop will

execute some code while some condition

remains true. It's fairly useful for

verifying user input. If a user types in

some input that is not valid, you can

reprompt them. And there's many other

uses that we'll discuss in the future.

But yeah, those are while loops in

Python. Why hello everybody. In today's

video, we'll be creating a compound

interest calculator in Python. For those

that don't know, interest is a charge

for the privilege of borrowing money to

some individual or organization. When

you place money in a bank account, you

typically acrue interest. We'll create a

program to tell you what your new

balance will be after acrewing interest

for so many years. But the user is going

to decide the initial principle. That's

the investment, the rate of interest,

and the time in years that this balance

has been acrewing interest. So let's

begin. Let's declare three variables. A

principle, a rate, that is rate of

interest, and time. Time will be in

years. We've recently learned about

while loops. I would like to include

those within this program just so we get

the hang of using them. We will ask the

user to type in an initial principal

investment. We will continue to prompt

the user to type in a principle that's

above zero. Our condition will be while

principal is less than or equal to zero.

We will take our principal assign it

some user

input. Enter the principal

amount. Then we would like to type cast

our input as a floatingoint number.

If our user input principle is less than

or equal to zero, we need to inform the

user

principle can't be less than or equal to

zero. So I'm going to test my program by

printing the principal at the end. Just

temporarily enter the principal amount.

I can't type a negative number and

continue. What if my investment was

negative

$1,000? Principal can't be less than or

equal to zero. How about zero? Nope.

Can't do that either. Is a,000. Okay?

Yep. A,000 works. That is for the

principal. Let's copy this while loop.

Paste it. Replace principal with rate.

This is the rate of

interest. Enter

the interest rate.

interest rate can't be less than or

equal to

zero. Then let's copy this again. Paste

it. Change rate to

time. Let's type cast our input as an

integer because we're working with whole

years. Enter the time in years.

time can be less than or equal to

zero. I'm going to print my principal,

rate, and

time. We have

principal, rate,

time. Okay, we know that principle

works. Enter the interest rate. Can my

interest rate be -1? No, it can't. Can

it be zero? Nope. How about 10? 10%. All

right, that works. Time. Can time be

zero? No, it can't. Can my time be

negative 1? No, it can't. What about 3

years? All right, so we know that our

while loops are working. Now, here's the

formula to calculate interest.

Let's say our total, that's our total

balance equals our principal

times 1 + our rate divided by 100. I'm

going to enclose this function with the

set of

parenthesis. This portion of our

function will take our interest rate,

which is a whole number, then create a

decimal. Enclose this function within

the power function.

raise this function to the power of time

and that is how to calculate compound

interest then we will print the new

balance I'll use an

fstring balance after our variable

time the word

years I'll add a placeholder we will add

our

total then I'll include a dollar sign

maybe this will be in dollars but pick

any unit of currency you would like. I

will format this variable with the

format specifier. We will display two

decimal places 2F. Okay, let's try this.

Enter the principal amount. I invest

$1,000 into maybe the stock

market. The interest rate is maybe 10%

this year. The time in years will be 1.

So, after one year at 10% interest, my

new balance is

$1,100. Let's try it one more time for

good measure. Maybe $500 with an

interest rate of 7 over 2 years. Your

new balance would be

$57245. All right. Now, there is another

way of writing this program. What if we

would like to allow the user to enter in

values that are equal to zero while

principal is less than zero? If

principal is less than zero, principal

can't be less than zero. Let's do that

for

rate. Interest can't be less than

zero.

Time can't be less than zero. Here's

what happens to our program. Remember

that we're declaring our variables at

the

top. Uh nothing happens. We go straight

to the results. So the reason that this

is happening is that when we reach the

while loops, this condition is false

from the beginning. We never end up

entering these while loops. We skip over

them because these three conditions are

all false. We can write a different

variation of this while loop where we

could say while true. True is a boolean.

That means this while loop will continue

forever unless we explicitly break out

of the while loop. We're going to add an

else

clause. Else we will break. Break will

break out of a

loop. With our second while loop, change

rate is less than zero to while true.

Then we will add an else

clause. Else break out of the

loop. While

true.

Else break out of the loop. We should be

able to enter zero values in

now. Enter the principal amount. 0 0 0.

Balance after 0 years is

$0. This should work the same as before,

but we should be allowed to enter in

zero values.

$1,000. Interest rate of zero after one

year is still

$1,000. Well, okay then everybody. I

thought that would be an interesting

project to create now that we know how

while loops work. You could write either

a standard while loop with a condition

such as principle is less than or equal

to zero or you could say while true.

This loop would continue forever. You

would need to explicitly break out of

the while loop using this break keyword

which we'll cover again in four loops.

But yeah, that is a compound interest

calculator in Python.

Hey everybody, in this topic I need to

explain for loops. A for loop will

execute a block of code a fixed number

of times. You can iterate over a range,

a string, a sequence, anything that is

considered iterable. I'll have more

examples for you in future topics. There

is a lot of overlap where you could use

either a while loop or a for loop, but

for loops tend to be better in

situations where you have to do

something only a fixed number of times.

Here's an example. Suppose we need to

count to 10. If we were to use a for

loop, we could write something like

this. We would type four, then we would

need some sort of counter. Typically,

you see people write x. 4 x in, then we

will use the range function. What number

would we like to start at? I would like

to start at 1, then count to 10. But the

second number is exclusive. So really,

we're going to write 11 if we want to

count to 10.

So then colon then hit enter. Whatever

code you would like to repeat a certain