Question

How can I extend a builtin class in python? I would like to add a method to the str class.
I’ve done some searching but all I’m finding is older posts, I’m hoping someone knows of something newer.

Answer 1

Just subclass the type

>>> class X(str): ...     def my_method(self): ...         return int(self) ... >>> s = X('Hi Mom') >>> s.lower() 'hi mom' >>> s.my_method() Traceback (most recent call last):   File '<stdin>', line 1, in <module>   File '<stdin>', line 3, in my_method ValueError: invalid literal for int() with base 10: 'Hi Mom'  >>> z = X('271828') >>> z.lower() '271828' >>> z.my_method() 271828