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https://github.com/clarete/forbiddenfruit

Patch built-in python objects
https://github.com/clarete/forbiddenfruit

monkey-patching python

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Patch built-in python objects

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[![Build Status](https://travis-ci.org/clarete/forbiddenfruit.png?branch=master)](https://travis-ci.org/clarete/forbiddenfruit)



# Forbidden Fruit



![Forbidden Fruit](logo.png)



This project allows Python code to extend built-in types.



If that's a good idea or not, you tell me. The first need this project

attended was allowing a [Python assertion

library](https://github.com/gabrielfalcao/sure) to implement a similar

API to [RSpec

Expectations](https://github.com/rspec/rspec-expectations) and

[should.js](https://shouldjs.github.io/). But people got creative and

used it to among other things [spy on

things](https://github.com/ikamensh/flynt/blob/43a64ac1a030be79741402d8920a6da253a96670/src/flynt/file_spy.py)

or to [integrate

profiling](https://github.com/localstack/localstack/blob/e38eae0d1fe442924f4256d4bc87710a4cb6f142/localstack/utils/analytics/profiler.py).



## Tiny Example



It basically allows you to patch built-in objects, declared in C through

python. Just like this:



1. Add a new method to the `int` class:



```python

from forbiddenfruit import curse



def words_of_wisdom(self):

    return self * "blah "



curse(int, "words_of_wisdom", words_of_wisdom)



assert (2).words_of_wisdom() == "blah blah "

```



2. Add a `classmethod` to the `str` class:



```python

from forbiddenfruit import curse



def hello(self):

    return "blah"



curse(str, "hello", classmethod(hello))



assert str.hello() == "blah"

```



### Reversing a curse



If you want to free your object from a curse, you can use the `reverse()`

function. Just like this:



```python

from forbiddenfruit import curse, reverse



curse(str, "test", "blah")

assert 'test' in dir(str)



# Time to reverse the curse

reverse(str, "test")

assert 'test' not in dir(str)

```



**Beware:** `reverse()` only deletes attributes. If you `curse()`'d to replace

a pre-existing attribute, `reverse()` won't re-install the existing attribute.



### Context Manager / Decorator



`cursed()` acts as a context manager to make a `curse()`, and then `reverse()`

it on exit. It uses

[`contextlib.contextmanager()`](https://docs.python.org/3/library/contextlib.html#contextlib.contextmanager),

so on Python 3.2+ it can also be used as a function decorator. Like so:



```python

from forbiddenfruit import cursed



with cursed(str, "test", "blah"):

    assert str.test == "blah"



assert "test" not in dir(str)



@cursed(str, "test", "blah")

def function():

    assert str.test == "blah"



function()



assert "test" not in dir(str)

```



## Compatibility



Forbbiden Fruit is tested on CPython 2.7, 3.0, and 3.3-3.7.



Since Forbidden Fruit is fundamentally dependent on the C API,

this library won't work on other python implementations, such

as Jython, pypy, etc.



## License



Copyright (C) 2013,2019  Lincoln Clarete 



This software is available under two different licenses at your

choice:



### GPLv3



This program is free software: you can redistribute it and/or modify

it under the terms of the GNU General Public License as published by

the Free Software Foundation, either version 3 of the License, or

(at your option) any later version.



This program is distributed in the hope that it will be useful,

but WITHOUT ANY WARRANTY; without even the implied warranty of

MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

GNU General Public License for more details.



You should have received a copy of the GNU General Public License

along with this program.  If not, see .



### MIT



Permission is hereby granted, free of charge, to any person obtaining a copy

of this software and associated documentation files (the "Software"), to deal

in the Software without restriction, including without limitation the rights

to use, copy, modify, merge, publish, distribute, sublicense, and/or sell

copies of the Software, and to permit persons to whom the Software is

furnished to do so, subject to the following conditions:



The above copyright notice and this permission notice shall be

included in all copies or substantial portions of the Software.



THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,

EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF

MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND

NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS

BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN

ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN

CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE

SOFTWARE.



### Logo by



Kimberly Chandler, from The Noun Project



### Changelog



#### 0.1.4



  * Add cursed() context manager/decorator

  * Conditionally build test C extension

  * Allow cursing dunder methods with non functions

  * Fix dual licensing issues. Distribute both GPLv3 & MIT license

    files.