Detailed explanation of the usage of python function bool([x])

bool([x])

English description: Convert a value to a Boolean, using the standard truth testing procedure. If x is false or omitted, this returns False; otherwise it returns True. bool is also a class, which is a subclass of int. Class bool cannot be subclassed further. Its only instances are False and True.

New in version 2.2.1.

Changed in version 2.3: If no argument is given, this function returns False.

Chinese description: Convert x to Boolean type, if x By default, False is returned, and bool is also a subclass of int;

Parameter x: any object or default; everyone noticed: [x] is used here, indicating that the x parameter is optional. If no parameters are given, False will be returned.

Version: The new function introduced in python 2.2.1 will return False if no parameters are passed after python2.3.

Note: This function can also be used normally in python3

Example:

>>> bool(0)
False
>>> bool("abc")
True
>>> bool("")
False
>>> bool([])
False
>>> bool()
False
>>> issubclass(bool, int) #bool是一个subclass int
True

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