Python: True, False (boolean)

True and False are literal values of boolean type.

print(type(True))  # <class 'bool'>
print(type(False))  # <class 'bool'>

What Value Evaluates to True?

In a if statement,

• non-empty things, and number 1, eval to True.
• None, zero, and empty things eval to False.

Following evaluates to False:

• False → A builtin literal expression.
• None → A builtin literal expression.
• 0 → Zero.
• 0.0 → Zero, float.
• "" → Empty string.
• [] → Empty list.
• () → Empty tuple.
• {} → Empty dictionary.
• set([]) → Empty set.
• frozenset([]) → Empty frozen set.

bool function

You can use the function bool to test.

# all the following are True

print(bool(3))
print(bool("abc"))

# all the following are False

print(bool(None))
print(bool([]))
print(bool(0))
print(bool(""))