MagicBuiltins - define methods on built-in types in python

magicbuiltins.py

import ctypes as c

class PyObject_HEAD(c.Structure):
    _fields_ = [
        ('HEAD', c.c_ubyte * (object.__basicsize__ -
                              c.sizeof(c.c_void_p))),
        ('ob_type', c.c_void_p)
    ]

_get_dict = c.pythonapi._PyObject_GetDictPtr
_get_dict.restype = c.POINTER(c.py_object)
_get_dict.argtypes = [c.py_object]

def get_dict(object):
    return _get_dict(object).contents.value

def setattr_builtin(builtin, method_name, func):
  # don't forget func needs to be defined and must have self as first arg
  get_dict(builtin)[method_name] = func



# usage

def add100(self):
  return self + 100
    
setattr_builtin(int, 'add100', add100)


>>>i = 10
>>>i.add100()
>>>110