Does Python Guarantee that `False` and `True` Always Equal 0 and 1?

Are False and True Guaranteed to Equal 0 and 1 in Python?

In Python, it is common practice to associate the False and True Boolean values with the integers 0 and 1. However, is this correspondence guaranteed by the language, or is it merely an implementation detail that could change in future versions?

Implementation Details vs. Language Guarantees

In Python 2.x, True and False are not explicitly defined as keywords, and their values can be reassigned. However, even in this case, comparisons still return the correct True and False values.

In Python 3.x, True and False are officially defined as keywords. This guarantees that their values will always be equal to 1 and 0, respectively.

Inheritance Relationship

Underlying the equivalence between Booleans and integers in Python is the fact that bool inherits from int. This inheritance relationship ensures that Booleans can be used in contexts expecting integers, such as list indexing.

Official Documentation

The Python documentation explicitly states that Booleans inherit from integers:

object
       |
     int
       |
     bool

The documentation also clarifies that Booleans behave like integers 0 and 1 in almost all contexts, except when converted to strings.

Conclusion

Based on the documentation and the current implementation of Python, it is safe to assume that False and True will always be equal to 0 and 1, respectively. However, if Python 4 introduces significant changes to the integer inheritance hierarchy, this assumption may no longer be valid.

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