Comparison, Logical, and Membership Operators in Python | Python for Beginners

Summary

This video tutorial offers a comprehensive overview of Python's comparison, logical, and membership operators. It explains how to use operators like '==', '!=', '>', '<', '>=', and '<=' to compare values. The tutorial also covers logical operators 'and', 'or', and 'not', illustrating their use with examples. Finally, it introduces membership operators 'in' and 'not in' to check for the presence of values within sequences, enhancing understanding of fundamental Python operations.

Takeaways

• 🔢 **Comparison Operators**: Python uses comparison operators like `==` (equal), `!=` (not equal), `>` (greater than), `<` (less than), `>=` (greater than or equal to), and `<=` (less than or equal to) to compare values.
• ❌ **Literal Assignment Error**: Trying to compare a literal like `10 == 10` without assignment will result in an error because it's interpreted as an assignment attempt.
• 📌 **Boolean Results**: Comparison operations return boolean values (`True` or `False`).
• 🔄 **Comparing Different Types**: You can compare different data types like numbers and strings using comparison operators.
• 🔄 **Variable Comparison**: Variables can be compared to check if they hold the same value.
• 📈 **Logical Operators**: Logical operators `and`, `or`, and `not` are used to combine comparison operations.
• 🔒 **AND Operator**: The `and` operator returns `True` only if both conditions are `True`.
• 🔄 **OR Operator**: The `or` operator returns `True` if at least one of the conditions is `True`.
• ❌ **NOT Operator**: The `not` operator inverts the result of a condition, turning `True` to `False` and vice versa.
• 📚 **Membership Operators**: `in` and `not in` are used to check if a value or string is present within another sequence.
• 🍦 **String Membership**: You can use `in` to check if a substring exists within a larger string.
• 📝 **List Membership**: Similarly, `in` can be used to check if an element is in a list, and `not in` for its absence.

Q & A

What are comparison operators in Python?

Comparison operators in Python are used to compare two values to determine their relationship. They include operators like '==' for equality, '!=' for inequality, '>' for greater than, '<' for less than, '>=' for greater than or equal to, and '<=' for less than or equal to.

Why can't you assign a value to a literal in Python?

In Python, you cannot assign a value to a literal because literals are not variables. They represent fixed values and cannot be reassigned. For example, trying to assign a value to '10' directly would result in an error because '10' is not a variable but a literal number.

How do you check for equality in Python?

To check for equality in Python, you use the '==' operator. For example, '10 == 10' would return 'True' because both sides of the operator are equal.

What is the output of '10 != 50' in Python?

The expression '10 != 50' checks if 10 is not equal to 50, which is true, so the output would be 'True'.

Can comparison operators be used with strings in Python?

Yes, comparison operators can be used with strings in Python. They compare the strings based on alphabetical order. For example, 'vanilla != chocolate' would return 'True' because 'vanilla' comes after 'chocolate' in the alphabet.

What is the purpose of logical operators in Python?

Logical operators in Python are used to combine multiple conditions. They include 'and', 'or', and 'not'. 'and' returns True if both conditions are True, 'or' returns True if at least one condition is True, and 'not' inverts the result of a condition.

How does the 'and' operator work in Python?

The 'and' operator in Python returns True only if both of the conditions it combines are True. If both conditions are True, the overall result is True; otherwise, it's False.

What is the result of '10 > 50 or 50 > 10'?

The expression '10 > 50 or 50 > 10' uses the 'or' operator. Since one of the conditions ('50 > 10') is True, the overall result is True, even though the other condition ('10 > 50') is False.

How can you check if a value is in a list using membership operators?

To check if a value is in a list, you can use the 'in' membership operator. For example, if you have a list called 'scoops' containing [1, 2, 3, 4, 5], then '2 in scoops' would return True because 2 is an element of the list.

What does the 'not in' operator do in Python?

The 'not in' operator in Python checks if a specified value is not present in a sequence. If the value is not found, it returns True. For example, '6 not in scoops' would return True if 'scoops' is a list that does not contain the number 6.

Outlines

00:00

🐍 Introduction to Comparison and Logical Operators in Python

This paragraph introduces comparison and logical operators in Python. It explains that operators are used to perform operations on variables and values, such as comparing two values to see if they are the same or different. The script goes on to demonstrate how to use the equality operator (==), inequality operator (!=), greater than (>), less than (<), greater than or equal to (>=), and less than or equal to (<=) operators. It also clarifies that attempting to assign a value directly to a literal will result in an error, as this is not how Python works. The script then shows how to correctly use these operators to get a boolean output of either True or False. It also covers the use of these operators with strings and variables, and introduces logical operators such as 'and', 'or', and 'not', explaining how they work with comparison operators.

05:01

🔍 Exploring Membership Operators in Python

The second paragraph focuses on membership operators in Python, which are used to check if a value or string is within another value or string. It explains the 'in' and 'not in' operators, showing how they can be used to search for the presence of a specified value within an object. The script provides examples using strings and lists, demonstrating how to check if a word is part of a larger string or if an element is within a list. It also shows how to use these operators to return True or False based on whether the specified value is found within the sequence. The examples include checking for the presence of a word in a sentence and checking if a number is within a list of numbers. The paragraph concludes with a brief mention of the practicality of these operators in Python programming.

Keywords

💡Comparison Operators

Comparison operators are used to compare values and variables in Python. They are fundamental for conditional statements and loops. In the video, the speaker explains how to use operators such as '==' for equality, '!=' for inequality, '>' for greater than, '<' for less than, '>=' for greater than or equal to, and '<=' for less than or equal to. These operators return a boolean value (True or False) based on the comparison, which is central to controlling the flow of a program.

💡Membership Operators

Membership operators are used to check if a value or a sequence is present within another object. The script mentions 'in' and 'not in' operators, which are used to verify the presence of a substring in a string or an element in a list. For example, the speaker demonstrates that 'love in ice_cream' returns True because 'love' is a substring of 'ice_cream'. These operators are vital for checking conditions in data structures.

💡Literal

A literal in programming refers to a fixed value that appears directly in the code. The video script mentions an error message 'cannot assign to literal', which occurs when trying to assign a value to a non-variable entity like a number or string directly. This illustrates the importance of understanding the difference between variables and literals in Python.

💡Logical Operators

Logical operators are used to combine multiple conditions in Python. The script discusses 'and', 'or', and 'not'. The 'and' operator returns True only if both conditions are True, 'or' returns True if at least one condition is True, and 'not' inverts the boolean value of a condition. These operators are crucial for creating complex conditional statements that are used to control program logic.

💡Boolean Value

A boolean value in Python is either True or False, representing a logical state. The video explains that comparison operators return boolean values, which is essential for making decisions in a program. For example, '10 == 10' returns True, indicating that the condition is met, while '10 != 50' returns True, indicating the condition is not met.

💡Variables

Variables in Python are used to store data values. The script mentions assigning values to variables like 'x = 'vanilla'' and 'y = 'chocolate''. Variables are essential for manipulating data and are often used in conjunction with comparison and membership operators to perform operations and make decisions.

💡Strings

Strings are sequences of characters in Python. The video uses strings to demonstrate comparison and membership operators. For example, 'vanilla != chocolate' compares two string literals and 'love in ice_cream' checks for the presence of a substring. Strings are a fundamental data type in Python used for text manipulation.

💡Lists

Lists are ordered, mutable collections of items in Python. The script creates a list 'scoops = [1, 2, 3, 4, 5]' and uses membership operators to check for the presence of elements within it, such as '2 in scoops'. Lists are versatile data structures used for storing and managing collections of items.

💡Conditional Statements

Conditional statements are used to perform different actions based on different conditions. The video implicitly discusses conditional statements by explaining how comparison and logical operators are used to evaluate conditions. For example, 'if 10 > 5:' would be a conditional statement that executes code if the condition (10 being greater than 5) is True.

💡Assignment

Assignment in Python is the process of binding a value to a variable name. The script mentions an incorrect attempt at assignment '10 = 10', which is not valid because assignment is meant for variables, not literals. Correct assignment would be 'x = 10', where 'x' is a variable and '10' is the value being assigned.

Highlights

Introduction to comparison, logical, and membership operators in Python

Explanation of the equal (==) operator for comparing values

Demonstration of the does not equal (!=) operator

Comparison of strings using the not equal operator

Using comparison operators with variables

Explanation of the less than (<) operator

Use of the less than or equal to (<=) operator

Demonstration of the greater than (>) and greater than or equal to (>=) operators

Introduction to logical operators: and, or, and not

Example of using the and operator with comparison statements

Explanation of how the or operator works with comparison statements

Demonstration of the not operator reversing the result of a comparison

Introduction to membership operators: in and not in

Using the in operator to check for substrings within a string

Example of using the in operator with a list to check for membership

Demonstration of the not in operator to verify absence of an element in a list

Practical application of membership operators in variable assignment and comparison

Conclusion and call to action for viewers to like and subscribe

Transcripts

hello everybody today we're going to be

taking a look at comparison logical and

membership operators in python operators

are used to perform operations on

variables and values for example you're

often going to want to compare two

separate values to see if they are the

same or if they're different within

python and that's where the comparison

operator comes in right here you can see

our operators you can also see what they

do so this equal sign equal sign stands

for equal we have the does not equal the

greater than less than greater than or

equal to and less than or equal to and

honestly i use these almost every single

time i use python so these are very

important to know and know how to use so

let's get rid of that really quickly and

actually start writing it out and see

how these comparison operators work in

python the very first one that we're

going to look at is equal to now you

can't just say 10 is equal to 10. let's

try running that really quickly by

clicking shift enter

it's going to say cannot assign to

literal that's because this is like

assigning a variable we're trying to say

10 is equal to 10 and then we can call

that 10 later but that's not how this

actually works what we're trying to do

is to determine whether 10 is equal to

10. so we're going to say equal sign

equal sign and then if we run that by

clicking shift enter again it's going to

say true now if we put something else

like 50 in there and we try to run this

it's going to say false so really what

you're going to get when you use these

comparison operators is either a true or

a false if we take this right down here

we can also say does not equal and we're

going to use an exclamation point equal

sign and that says 10 is not equal to 50

and that should be true you can also

compare strings and variables so let's

go right down here and we're going to

say

vanilla

is not equal

to chocolate

and when we run this it'll say false now

if it was the same just like when we did

our numbers it should say true and we

can also compare variables so we'll say

x is equal to

vanilla

and y is equal to

chocolate

and then when we come down here we can

say x is equal to y

and it'll give us a false and we say

x

is not equal to y

and it'll give us a true the next one

that we're going to take a look at is

the less than so let's copy this one

right up here

let's scroll down

and let's say 10

is less than 50. now this will come out

as true now let's say we put a 10 in

here before 10 was of course less than

50 but is 10 less than 10

no that's false because they are the

same so if we want an output that is

true all we would have to add is an

equal sign right here and this would say

10 is less than or it is equal to 10.

and now it's true

of course we can say the exact same

thing by saying greater than so 10 is

equal or greater than 10. that'll be

true because 10 is equal to 10. we can

also say 50 is greater or equal to 10

because 50 is obviously greater than 10.

now let's look at logical operators that

are often combined with comparison

operators so our operators are and or

and not so if you have an and that

returns true if both statements are true

if it's or only one of the statements

has to be true and the not basically

reverses the result so if it was going

to return true it would return false i

don't use this not one a lot but i will

show you how it works so let's actually

test that out so before we were saying

10 is greater than 50 and of course this

returned false so now let's add a

parenthesis around this 10 is greater

than 50 and we're going to say and we'll

do an open parenthesis 50 is greater

than 10.

now this statement right here is true 50

is greater than 10 so we have a true

statement and a full statement but this

and is going to look at both of them

it's going to say they both need to be

true in order to return a true so let's

try running this

and we still have a false if we want it

to return true we're going to change

this to make it a true statement so 70

is greater than 50 and 50 is greater

than 10 when we run this it should

return true now let's look at the or so

let's copy this

and we'll say

10 is greater than 50

or

50 is greater than 10. now this is a

false statement and this is a true

statement so if even one of them is a

true statement the output should be true

and again we can do this even with

strings so we can do vanilla

and

chocolate

there we go

and vanilla is actually greater than

chocolate because v is a higher number

in the alphabetical order so v is like

20 something whereas chocolate is three

right so it actually looks at the

spelling for this so if we say or here

it will come out true and if we say and

here it should also be true because v is

greater than c and 50 is greater than 10

so this should also be true

now let's copy this right here

and we're going to say not

so what we had before is 50 is greater

than 10 that returned true but now all

we're doing is putting not in front of

it so instead of returning true it's

going to return false so now let's take

a look at membership operators and we

use this to check if something whether

it's a value or a string or something

like that is within another value or

string or sequence our operators are in

and not in so it's pretty simple if it's

in it's going to return true if the

sequence with a specified value is

present in the object just like we were

talking about and for not in it's

basically the exact same thing if it's

not in that object so let's start out by

taking a look at a string we're going to

say ice underscore cream is equal to

i love

chocolate ice cream

and then we're going to say love

in

ice underscore cream and that will

return true so all we're doing is

searching if the word love or that

string is in this larger string we could

also just do that by literally copying

this and putting this where this is so

we can check is this string part of this

string and it'll say true we can also

make a list so we'll say scoops is equal

to and then we'll do a bracket and we'll

say one two three four five

and then we'll say two

in scoops so all we're doing is

searching to see if two is within this

list and that should return true now if

we put a six here and we said not in

it will also return true because 6 is

not in scoops and that is true

and just like we did we could also say

wanted underscore scoops and we'll say 8

so i wanted 8 scoops so we can say

wanted scoops in scoops and this should

return true because there's not an eight

within the scoops that we wanted

and if we said in

and we said we wanted eight is that

within our list that we created and

that's going to return a false so that

is a quick breakdown of comparison

logical and membership operators i hope

that this was helpful thank you guys so

much for watching if you like this video

be sure to like and subscribe and i will

see you in the next video

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