Truthy and falsy values in Python - Cheat Sheet & Quick Revision

Recall & Review

beginner

What does it mean when a value is truthy in Python?

A truthy value is any value that Python treats as True when used in a condition, like in an if statement. For example, non-zero numbers and non-empty strings are truthy.

beginner

What is a falsy value in Python?

A falsy value is any value that Python treats as False in a condition. Examples include 0, '' (empty string), [] (empty list), None, and False itself.

beginner

Which of these values is falsy in Python? <br> A) 1 <br> B) '' <br> C) 'False' <br> D) [1, 2]

The correct answer is B) ''. An empty string is falsy. The others are truthy because 1 is non-zero, 'False' is a non-empty string, and [1, 2] is a non-empty list.

intermediate

How does Python decide if a value is truthy or falsy in an if statement?

Python uses the built-in bool() function internally to check the truthiness of a value. If bool(value) returns True, the value is truthy; if it returns False, the value is falsy.

beginner

Give two examples of truthy and two examples of falsy values in Python.

Truthy examples: 42 (non-zero number), 'hello' (non-empty string).<br>Falsy examples: 0 (zero), [] (empty list).

Which of the following is considered falsy in Python?

A ''

B 1

C 'False'

D [0]

An empty string ('') is falsy. 'False' is a non-empty string, so it is truthy.

What does Python use internally to check if a value is truthy or falsy?

A int()

B bool()

C float()

D str()

Python uses the bool() function to determine the truthiness of a value.

Which of these values is truthy?

A False

B None

C [1, 2, 3]

D 0

Non-empty lists like [1, 2, 3] are truthy.

Is the number -5 truthy or falsy in Python?

A None of the above

B Falsy

C Depends on context

D Truthy

Any non-zero number, including negative numbers, is truthy.

Which of these is NOT a falsy value in Python?

A ' ' (a space)

B []

C 0.0

D None

A string with a space (' ') is non-empty, so it is truthy.

Explain what truthy and falsy values are in Python and give examples of each.

Think about how Python treats values in conditions like if statements.

How does Python determine if a value is truthy or falsy when used in a condition?

Consider what happens inside an if statement.