intercepts 0.2.0

Intercept function and method calls

Intercepts

Intercepts allows you to intercept any function call in python and handle it in any manner you choose. For example, you can pre-process the inputs to a function, or apply post-processing on its output. Intercepts also allows you to completely replace a function with a custom implementation.

>>> increment(41)
42
>>> intercepts.register(increment, handler)
>>> increment(41)
40
>>> intercepts.unregister(increment)
>>> intercepts.register(increment, handler2)
>>> increment(41)
'The answer is: 42'
>>> intercepts.unregister_all()

Handler functions receive the intercepted function as their first argument, as well as all of the arguments to the intercepted function.

>>> def handler(func, num):
...  result = func(num)
...  return num - (result - num)
>>> def handler2(func, *args, **kwargs):
...  return 'The answer is: %s' % func(*args, **kwargs)

The intercepts module also allows intercepting python built-in functions, such as print and sorted. For best results, the intercepts module should be the first module imported.

>>> def print_handler(print_func, message):
...  print_func(''.join(reversed(message)))
>>> print("Hello world")
Hello world
>>> intercepts.register(print, print_handler)
>>> print("Hello world")
dlrow olleH

Requirements

Intercepts requires python 3.3+. There are currently no additional dependencies.

Installation

Intercepts can be installed using pip.

$ pip install intercepts

Documentation

Sorry, we are in the very early stages of development so documentation is limited. There is some documentation in the docs directory, but for the most up-to-date documentation, use pydoc.

$ pydoc intercepts

This software is in early stages of development and may be unstable.