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Is false 0 in Python?

Published in Python Programming 2 mins read

Yes, in Python, the boolean value False is equivalent to the integer 0.

This equivalence is a fundamental aspect of Python's type system and truthiness evaluation. It means that you can use 0 in places where a boolean value is expected, and Python will treat it as False. Similarly, you can use False in arithmetic operations, and Python will treat it as 0.

Truthiness in Python

In Python, every object has a boolean value associated with it. This is often referred to as its "truthiness". While True and False are the explicit boolean values, other types also have implicit boolean interpretations.

  • False Values: The following are considered False in Python:

    • False (boolean)
    • None
    • 0 (integer)
    • 0.0 (float)
    • '' (empty string)
    • [] (empty list)
    • {} (empty dictionary)
    • () (empty tuple)
    • set() (empty set)
    • Objects that define a __bool__() or __len__() method that returns False or 0, respectively.

  • True Values: Anything that is not listed above is generally considered True.

Examples

Here are a few examples to illustrate this:

if 0:
    print("This will not print")  # 0 is False
else:
    print("This will print")      # Because 0 is False

if False:
    print("This will not print") # False is False
else:
    print("This will print")      # Because False is False

print(False == 0)  # Output: True

print(True == 1)   # Output: True

print(False + 5)  # Output: 5 (False is treated as 0)

Implications

This behavior can be useful in certain situations, such as concisely checking for default values or implementing simple flags. However, it's important to be aware of this equivalence to avoid unexpected behavior in your code. Using explicit boolean values (True and False) can often improve readability, especially in more complex logic.

Summary

False and 0 are interchangeable in Python's boolean context. Knowing this helps in understanding how Python evaluates conditions and performs type conversions. While convenient, use with caution to maintain code clarity.

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