Python Variables and Data Types

Summary

This Python tutorial covers the basics of variables, data types, and their applications. It introduces variables as essential building blocks, explaining their components: symbolic names, assignment operators, and values. The lesson delves into numeric data types, including integers and floats, with practical examples like calculating the probability of COVID-19 infection in British Columbia. It then explores strings, demonstrating how to manipulate and concatenate them using various methods. The tutorial also touches on boolean values and their role in conditional statements, setting the stage for future discussions on if statements and loops. The video promises more on advanced data types and variable naming conventions in the next installment.

Takeaways

• 🐍 Variables in Python are fundamental building blocks used to store data for easy access in code.
• 🔢 Variables can hold different data types, including integers, floats, strings, and booleans.
• 📈 Python automatically converts integers to floats when performing division, resulting in decimal values.
• 📝 Strings are sequences of characters enclosed in quotation marks and can include letters, numbers, and symbols.
• 🔍 The `type()` function can be used to check the data type of a variable in Python.
• 🧮 Basic mathematical operations like addition, subtraction, multiplication, division, and exponentiation can be performed on numeric data types.
• 🔗 String concatenation can be done using the `+` operator or within print statements using commas.
• 📑 The `format` method offers a more organized way to create formatted strings with variables.
• 🔁 Strings can be repeated using the multiplication operator (`*`) to repeat a string a specified number of times.
• 📊 Boolean values (`True` or `False`) are used in conditional statements and are integral to control flow in Python.
• 📘 Advanced data types, which can contain more than one value, will be covered in later lessons.

Q & A

What are the three elements that make up a variable in Python?

A variable in Python consists of a symbolic name, an assignment operator (usually the equality sign), and the value that is being stored.

How many basic data types are there in Python?

There are eight basic data types in Python.

What is an integer in Python and what does it represent?

An integer in Python represents whole numbers, which can be positive or negative.

How do you represent floating-point numbers in Python?

Floating-point numbers, or floats, in Python represent decimals and can also be positive or negative.

What is the purpose of the 'type' function in Python?

The 'type' function in Python is used to check the data type of a variable when you are unsure of it.

What happens to the data type when you divide two integers in Python?

When you divide two integers in Python, the result is a float, even if the division results in a whole number.

What is a string in Python?

A string in Python is a set of characters enclosed in quotation marks, which can include letters, numbers, punctuation, and spaces.

How can you concatenate strings in Python?

You can concatenate strings in Python using the plus operator, the comma operator within print statements, or the format method.

What are the two arithmetic operations that can be performed on strings?

The two arithmetic operations that can be performed on strings are concatenation using the plus operator and multiplication using the asterisk operator.

What is a boolean data type in Python and what values can it take?

A boolean data type in Python can only take two values: 'True' or 'False', represented with a capital 'T' and 'F' respectively.

How do you check for equality in Python?

To check for equality in Python, you use the double equality sign (==) instead of the single equality sign, which is used for assignment.

Outlines

00:00

🐍 Introduction to Variables and Data Types

This paragraph introduces the concept of variables in Python, explaining them as fundamental building blocks used to store data for easy access in code. It covers the three elements of variables: a symbolic name, an assignment operator (usually the equality sign), and the value to be stored. The paragraph also categorizes variables into different data types, such as numbers, words, and lists, and mentions that there are eight basic data types in Python. It starts with numeric data types, specifically integers (whole numbers) and floating-point numbers (decimals), and provides examples of how to declare and manipulate these types. The speaker also demonstrates how to perform basic arithmetic operations with these numeric types.

05:03

📝 Exploring Strings and Concatenation

The second paragraph delves into strings, which are sequences of characters enclosed in quotation marks. It explains that strings can include letters, numbers, punctuation, and spaces. The paragraph provides examples of declaring string variables and demonstrates how to print multiple variables in a single statement. It introduces string concatenation, showing how to connect strings using the plus operator and the comma operator within print statements. The speaker also explains how to use the format method for more organized string concatenation, filling in placeholders with variable values. Additionally, the paragraph touches on the limitations of mathematical operations with strings compared to integers and floats.

10:04

🔢 Arithmetic with Strings and Boolean Basics

This paragraph discusses the arithmetic operations that can be performed on strings, such as concatenation using the plus operator and multiplication with an integer or float using the asterisk operator. It then provides a real-life example of how strings can be used to personalize messages, similar to email newsletters. The paragraph concludes with an introduction to boolean data types, which can only be true or false. It explains the use of booleans in conditional statements and comparison operators, emphasizing their importance in upcoming lessons on control structures like if statements and while loops. The speaker also hints at the existence of more complex data types that will be covered later in the course.

Keywords

💡Variables

Variables in the context of the video are the fundamental building blocks in Python programming used to store data. They consist of a symbolic name, an assignment operator (often the equal sign), and a value. Variables allow programmers to store and manipulate data easily throughout their code. For example, the video uses 'dragons' as a variable to represent the number of dragons the presenter has.

💡Data Types

Data types refer to the various kinds of values that can be stored in variables. The video introduces eight basic data types in Python, including integers, floating-point numbers, strings, and booleans. Understanding data types is crucial for knowing how to manipulate and use data within a program.

💡Integers

Integers are a data type representing whole numbers, both positive and negative. In the video, integers are used to demonstrate basic arithmetic operations and to track the number of dragons. For instance, 'dragons' is an integer variable set to three, and 'dead_dragons' is another integer set to two.

💡Floating-Point Numbers

Floating-point numbers, or floats, represent real numbers and can include decimals. They are used when precision to a specific number of decimal places is necessary. In the video, a floating-point number is used to calculate the probability of getting sick with COVID-19 in British Columbia.

💡Type Function

The 'type' function in Python is used to determine the data type of a variable. This is demonstrated in the video when the presenter checks if the variable 'prob' is a float, which it is because the result of the division operation resulted in a decimal value.

💡Strings

Strings are sets of characters enclosed in quotation marks, which can include letters, numbers, and punctuation. They are used to represent text in Python. The video provides examples of string variables such as 'pet', 'pet_name', and 'pet_age', and shows how to concatenate them to form sentences.

💡Concatenation

Concatenation is the process of joining two or more strings together. The video explains how to concatenate strings using the plus operator and the comma operator within print statements. It also introduces the 'format' method as a more organized way to concatenate strings with variables.

💡Boolean

Booleans are a data type that can only be one of two values: True or False. They are used in conditional statements to evaluate whether a certain condition is met. The video uses a boolean variable 'my_boolean' to demonstrate a conditional statement where Python evaluates if 3 is less than 6.

💡Conditional Statements

Conditional statements are used to perform different actions based on whether a condition is true or false. The video briefly mentions that boolean values are integral to if statements and while loops, which will be covered in future lessons. An example given is checking if 3 is less than 6.

💡Arithmetic Operations

Arithmetic operations are mathematical calculations performed using numbers. The video demonstrates basic arithmetic operations such as addition, subtraction, multiplication, division, and exponentiation using integers and floating-point numbers.

💡Assignment Operator

The assignment operator, often the equal sign (=), is used to assign values to variables. It is a fundamental concept in programming for storing data. The video explains that variables are created with a name, an assignment operator, and a value.

Highlights

Variables are basic building blocks in Python used to store data.

Variables consist of a symbolic name, an assignment operator, and a value.

Python has eight basic data types for different kinds of data storage.

Integers represent whole numbers, both positive and negative.

Floating-point numbers or floats represent decimals.

An example of using integers to calculate the number of dragons remaining.

A real-life scenario using integers and floats to track COVID-19 cases.

Variables can be checked for their data type using the 'type' function.

Strings are sets of characters inside quotation marks.

Concatenation of strings can be done using the plus operator.

The format method is a favorite way to concatenate strings for its organization.

Boolean data type can only be true or false.

Conditional statements are used to evaluate true or false values.

Comparison operators are used to compare values in Python.

Boolean values are integral to if statements and while loops.

Advanced data types can contain more than one value.

The video will be continued in the next part focusing on variable naming rules.

Transcripts

[Music]

hi people welcome to Python lesson

number three where we'll talk about

variables and all the different types of

data we can store inside them variables

are very basic building blocks in Python

we use them to store pieces of data that

we'd like to easily access throughout

our code variables consists of three

different elements a symbolic name an

assignment operator which in most cases

will be the Equality sign and lastly the

value are looking to store and I've

included some examples for you guys so

check them out before you continue

variables are also being categorized

into different data types representing

numbers words and even lists of items

currently there are eight basic data

types in Python and let's actually take

a look at them so it can get more

familiar we'll start from the numeric

data types and our first one would be

integers integers represent whole

numbers positive or negative and you can

see some examples while floating-point

numbers or floats represent decimals

positive or negative as well and it's

the perfect time to start in your

notebook and Jupiter or call out

whichever you like and we'll take a look

at some coding examples so let's say I

have three dragons so we'll type dragons

equals three and randomly with no

particular reason let's say the two of

my dragons died so we'll type dead

underscore dragons equals two you know

the only thing left to do is to type a

simple formula and find out how many

dragons I actually have we'll type total

underscore dragons equals dragons - that

dragons kind of makes sense and make

sure you print the results so we'll do

print total underscore dragons and we

can run the cell with shift-enter

and we got one perfect well okay that

was way too easy and extremely unusual

so

see a real-life scenario where we can

use integers or floats so I live in

British Columbia Canada and lately I've

been keeping track of all the covert 19

cases in the province so I'm going to

use the up to date numbers from the

government website of the cases in BC

and we'll compare it to how many people

in total live here our first variable

will be named Kovac underscore BC and

it's equals to 1200 and 3 as we've seen

in the previous page while population

underscore BC is actually equals to 5

million and 71 thousand people that's a

lot and for now keep your variable names

identical to mine and we'll talk about

the naming rules later on it's time for

the formula so my probability of getting

sick we'll call it prob equals to Colvin

underscore BC / or / population

underscore BC and we'll print these and

shift-enter to run the cell and as you

see my chances of getting infected are

pretty low at least from this

perspective I actually want to point

your attention and do something

interesting that happened here we can

see that even though the variable prop

was created using two integers it ends

up falling under the float category

because we get a decimal there's

actually a very simple way of checking

the data type of a variable if you're

unsure we'll simply use the type

function so we do it by typing type and

inside round brackets we'll put our

variable prob and we'll wrap all of this

in a print statement so we can see the

results run the cell with shift-enter

and we can see that python interprets

the variable probe as a float let's

actually check the type of population BC

now we're expecting to see that it's an

integer but you never know it's always

good to check and we see that we got it

right perfect

in our last numeric example i'll show

the mathematical operations you can do

with basic Python and yes I mean the

absolute most basic Python so let's say

a equals 12 and B equals 3 we can find

out their sum by using plus we can find

out their difference by using minus we

can multiply using the asterisk we can

divide by using the slash and lastly we

can even do a square operation with two

asterisks the next datatype we'll talk

about is strings a string is any set of

characters inside quotation marks now

these characters can include letters

numbers or even punctuation symbols and

spaces basically as long as something is

wrapped inside quotation marks Python

will interpret it as a string let's see

some examples so let's get a few basic

details about our pets I'll type pet

equals and in my case that would be cat

inside quotation marks now the quotation

marks can be either single or double as

long as it's a matching pair now we'll

continue to cut underscore name which in

my case equals to me oh yes you can tell

I was very impressed with the matrix and

lastly pet underscore age in my case

equals two quotation marks for now here

I want you guys to note that even though

four is a whole number once we place it

inside quotation marks it does not count

as an integer anymore it counts as a

string automatically an integer would

have looked like this so if the value of

your variable is green that means you

got yourself a float or an integer and

if the value of your variable is

burgundy that means that it's a string

well at least in Jupiter

now let's print all three variables in

the exact same statement will type pet

coma pet name comma again and Pat age

shift enter and Wow

we desperately need a few connection

words luckily you don't really need to

create separate variables for every

piece of string you want to include so

let's start with some context inside a

print statement will start with

quotation marks and the words I have a

then will include the variable Pat using

a comma of course and then we'll write

his name is inside of quotation marks

then we'll include the Pat underscore

name we'll include the words and he is

following a comma and the variable Pet

underscore age and lastly finally coma

and the string years old now let's use

shift enter to run the cell now what

we've just done here is called string

concatenation which is fancy words for

connecting strings

note that concatenated using the coma

operator can only be done inside print

statements using comma anywhere else

will result in a completely different

action so don't do it just yet we'll get

to it when we'll talk about tuples

another thing we can do inside our print

statement is dividing it into lines

we'll use the new line literal which is

backslash N and while it looks a bit

crazy at first our results will now be

arranged a bit differently we now have

three lines instead of one and let's

actually delete our first print

statement we don't need it anymore

and we can also see that the new lines

begin exactly where we placed our

backslash and literal perfect in our

second example we'll start our

concatenated string inside a variable

we'll name it my underscore pet and

we'll use the plus operator to can

cata needed to the variable Pat and so

on and again using a coma-like in the

print statement above will not work here

coma as part of a variable value means a

completely different thing and now I'm

just adding a little bit of context

mostly to demonstrate we can use

multiple plus operators in the exact

same concatenation

so let's print our variable my

underscore pet and wow it works great

another cool way we can concatenate

strings is by using the format method

and this is probably my favorite way

because it's so much more organized will

type my underscore pet to equals I have

a curly brackets his name is curly

brackets and he is you guessed it right

curly brackets years old and right after

the closing quotation marks with no

spaces in between we type dot format and

inside the round brackets we're filling

in the blanks sequentially so first

we'll have pet then we'll have pet

underscore name and lastly we'll have

pet underscore age and we're separating

all of these with commas so don't forget

that now let's print the variable my

underscore Pat - and yes it works once

again so far we've talked about all

sorts of ways of combining these strings

but what else can we do with them

can we use some mathematical operations

like we did with integers and floats

let's have a look there are actually two

arithmetic operations we can use with

strings the first we're already familiar

with that would be the summation of two

strings by using the plus operator again

it's in the examples above and the

second is the multiplication of a string

by any integer or float so as you can

see in the current examples the plus

symbols

asterisks have completely different

meanings when handling strings but

what's the point in all this where can

we apply strings in real life you can

see that once we change a value in one

or two of our pet ID variables our print

statements are being modified

accordingly you can basically tailor

specific words inside your print

statement to make your message more

personal similarly to how every email

newsletter these days contains your name

somewhere on it rather than just a

general hello user greeting so there's

your real life example the last data

type we'll talk about today is boolean

and it's the easiest of them all because

it can only be one of two values it can

either be true with a capital T or false

with a capital F and let me explain with

an example so our variable my underscore

boolean is equal to and now it's time

for the conditional statement which in

our case will be 3 is less than 6

now Python is going to evaluate this

conditional statement and let you know

whether if it's true or false actually

we can wrap our condition inside round

brackets so it looks a bit more

organized we'll try the same but this

time we'll flip the side of the operator

so 3 is greater than 6 let's see what

python has to say about that and as you

can see 3 is indeed not greater than 6

here's a tricky question what happens if

we want to check for the Equality

instead do we still use the equal

operator and the answer is absolutely

not the equality symbol is an assignment

operator it's basically the glue that

holds a variable name in its value and

therefore we cannot use it to make

comparisons instead we'll use the double

equality sign which is the go-to symbol

in our case moreover there are plenty of

other comparison operators you can use

please take a look at the following list

and try to experiment with a few of

these and

as you experiment you may be wondering

what exactly can we do with this true or

false thing where does it come handy so

in the near future we'll learn all about

if statements and while loops where

boolean z' are an integral part of the

scheme so far we've only talked to about

four simple datatypes what about the

rest of them

the advanced datatypes contain more than

just one value as you can probably see

in the examples we can recognize some

strings and integers inside them and yet

they fall under completely different

categories so let's save these for a

later point in our course and we'll talk

about them after we master all the cool

things we can do with integers strings

floats and boolean and by things

I mean methods so stay tuned in the next

video we'll talk about the rules of

nathan in your variables just as I

promised earlier I just had to split

this lesson into two parts to keep it

slightly shorter and slightly more

bearable if you guys found this video

helpful please give it a thumbs up and I

will see you in less than three point

five very soon bye bye