Python Booleans and Comparison Operators

True and False

A boolean (bool) has only two values: True and False. You met them in chapter 4. In this topic, you'll see where they really come from: questions your program asks.

Think of a boolean as a light switch: on or off, yes or no. Nothing in between.

1234is_raining = False
has_umbrella = True
print(is_raining, has_umbrella)
print(type(is_raining))

The rules, again

• Capital first letter: True, False.
• No quotes: "True" is a string, not a boolean.

12print(type(True))
print(type("True"))

Booleans are answers

You'll rarely type True or False yourself. Most booleans come from comparing values: "is the score above 50?", "is the password right?". Python answers each question with True or False.

12score = 72
print(score > 50)

That > is a comparison operator. You'll learn all of them in the next lesson. In chapter 8, if will use these answers to make decisions, like the diamond in a flowchart.

A fun fact

Behind the scenes, True counts as 1 and False as 0:

1print(True + True)

You won't need this often, but it explains some surprising results later.

Booleans are True or False: the answers to yes-or-no questions.

Comparison Operators

Comparison operators compare two values and answer with a boolean:

12345age = 18
print(age > 10)
print(age < 10)
print(age == 18)
print(age != 18)

Think of a ticket counter

"Is the visitor at least 18?" becomes age >= 18. The answer is True or False, and later the program will let them in, or not.

Store the answer

A comparison is a value like any other, so you can store it:

123marks = 45
passed = marks >= 40
print("Passed:", passed)

>= and <= include the edge

5 > 5 is False, because 5 isn't bigger than itself. 5 >= 5 is True, because "or equal" includes it. Off-by-one mistakes here are very common, so think about the edge every time.

Common beginner doubt: "Can I write =>?" No: the = always comes second: >= and <=.

Comparisons ask a question and answer True or False.

= or ==?

This is the mix-up every beginner makes at least once, so let's settle it:

123age = 18
print(age == 18)
print(age == 21)

The first line stores 18. The print() lines ask questions about it.

A way to remember

Read = as "gets" and == as "is equal to?".

• age = 18 → "age gets 18".
• age == 18 → "is age equal to 18?"

One = gives a value. Two == ask a question.

What goes wrong

Using == when you meant = doesn't store anything. And using = inside a question breaks the code:

12age = 18
print(age = 18)

Python thought age = 18 inside print() was a parameter, like sep=. In chapter 8 you'll see that if age = 18: gives an error too. When you ask, use ==.

One = stores a value. Two == ask if two values are equal.

Comparing Text

Comparisons work on strings too. == checks that two strings are exactly the same:

123password = "sunny123"
print(password == "sunny123")
print(password == "Sunny123")

Exactly means exactly

Like variable names, string comparisons are case-sensitive: "Sunny" and "sunny" are different. Spaces count too:

12print("Sunny" == "sunny")
print("Hi" == "Hi ")

That extra space at the end of "Hi " makes them different. Hidden spaces are a common reason a "correct" answer is judged wrong.

A string vs a number

1print("5" == 5)

The text "5" and the number 5 are different types, so they're never equal. You'll learn how to convert one into the other in the next topic.

Greater and less with text

< and > compare strings in alphabetical order, letter by letter:

12print("apple" < "banana")
print("Zebra" < "apple")

The second one surprises people: every capital letter comes before every small letter in this order. So for alphabetical sorting, keep the case the same.

Think of a dictionary: "apple" comes before "banana", so "apple" < "banana" is True.

Text comparisons are exact: capitals, spaces and types all count.

Practice: Booleans

Solve these to lock in what you learned in this topic. Each one runs in your browser.

1. 40.Python Program to Compare Two NumbersEasySolve
2. 41.Python Program to Check If Two Passwords MatchEasySolve