Python bool() built-in function
From the Python 3 documentation
Return a Boolean value, True or False. x is converted using the standard truth testing procedure. If x is false or omitted, this returns False; otherwise, it returns True. The bool class is a subclass of int. It cannot be subclassed further. Its only instances are False and True.
Introduction
The bool() function in Python is a built-in function that converts a value to a Boolean (True or False). It follows the standard truth testing procedure, where values like 0, None, and empty collections are considered False, while most other values are True. This is fundamental for controlling the flow of your program with conditional statements.
Examples
Falsy Values
These values are considered False:
>>> bool(False)
# False
>>> bool(None)
# False
>>> bool(0)
# False
>>> bool(0.0)
# False
>>> bool('') # empty string
# False
>>> bool([]) # empty list
# False
>>> bool({}) # empty dict
# False
>>> bool(set()) # empty set
# False
Truthy Values
Most other values are considered True:
>>> bool(True)
# True
>>> bool(1)
# True
>>> bool(-1)
# True
>>> bool('hello')
# True
>>> bool([1, 2])
# True
>>> bool({'a': 1})
# True