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https://github.com/wimglenn/monkey-magic

Monkeypatch built-in types
https://github.com/wimglenn/monkey-magic

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Monkeypatch built-in types

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README 

        
Monkey Magic

============



Monkeypatch built-in types in Python.



Installation

------------



.. code-block:: bash



   pip install monkey-magic



Usage

-----



Suppose you define a function ``href`` that you want to contribute as a "method" on ``str``:



.. code-block:: python



   def href(self: str) -> str:

       """make a url string into a hyperlink"""

       return f'{self}'



Applying and then using it would look like this:



>>> from monkey_magic import monkeypatch

>>> monkeypatch(str, href)

>>> url = "www.example.com"

>>> url.href()

'www.example.com'



This patch affects all strings, globally, including literals. It will work regardless of whether the patch was applied before or after a string instance was created.



.. skip: next



.. code-block::



   >>> help(str.href)

   Help on function href:



   href(self: str) -> str

      make a url string into a hyperlink



>>> "href" in dir(str)

True

>>> "hello".href



>>> "hello".href()

'hello'



More Examples

-------------



Adding some pre-existing function:



>>> hi = """\

...     hello

...     world

... """

>>> import textwrap

>>> monkeypatch(str, textwrap.dedent)

>>> hi.dedent()

'hello\nworld\n'



Want to use a different name than the function's name?



.. code-block:: python



   import math



   def func(n):

       if n == 2 or n == 3:

           return True

       if n == 1 or n % 2 == 0:

           return False

       else:

           return all(n % i for i in range(3, int(1 + math.sqrt(n)), 2))



>>> monkeypatch(int, func, name="is_prime")

>>> 7 .is_prime()

True

>>> 8 .is_prime()

False



Contributing the unicode name function



>>> import unicodedata

>>> monkeypatch(str, unicodedata.name)

>>> "a".name()

'LATIN SMALL LETTER A'

>>> "💩".name()

'PILE OF POO'



Would you prefer that as a property instead of a method?



>>> monkeypatch(str, property(unicodedata.name), name="pname")

>>> "a".pname

'LATIN SMALL LETTER A'

>>> "🔥".pname

'FIRE'



To apply the same patch on a bunch of types:



.. code-block:: python



   @property

   def first(self):

       return next(iter(self))



>>> monkeypatch((str, bytes, tuple, list, dict), first)

>>> [1, 2].first

1

>>> (3, 4, 5).first

3

>>> "potato".first

'p'

>>> b"cafef00d".first

99

>>> {"k1": "v1", "k2": "v2"}.first

'k1'



Why does ``list.sort`` exist but ``dict.sort`` doesn't?



.. code-block:: python



   def sort(self, key=None, reverse=False):

       d_sort = {k: d[k] for k in sorted(self, key=key, reverse=reverse)}

       self.clear()

       self.update(d_sort)



>>> monkeypatch(dict, sort)

>>> d = {1: 1, 0: 0, 2: 2}

>>> d.sort()

>>> print(d)

{0: 0, 1: 1, 2: 2}

>>> d.sort(reverse=True)

>>> print(d)

{2: 2, 1: 1, 0: 0}

>>> d.sort(key=lambda k: k % 2)

>>> print(d)

{2: 2, 0: 0, 1: 1}



Just want an attribute, not a callable? That's fine.



>>> monkeypatch(list, 42, "number")

>>> [].number

42

>>> [1, 2].number

42



FAQ

---



... Why should I use this? Why not just use a function?

   You should not use this. Just use a function.



... Where are the tests?

   This ``README.rst`` is the test. The code-blocks in this document are actually `executed `_.



... Does this work in PyPy?

   The code uses implementation details of CPython. It will not work in PyPy.



... How to undo a patch?

   I don't know. When I try, Python segfaults. If you know how, `send me a PR `_.



... Did people really ask you these questions?

   Nope. I just made them up.