forked from varia/varia.website
You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
93 lines
2.4 KiB
93 lines
2.4 KiB
7 years ago
|
import inspect
|
||
|
|
import six
|
||
|
|
|
||
|
|
# Modifies class methods (or instances of them) on the fly
|
||
|
|
# http://blog.ianbicking.org/2007/08/08/opening-python-classes/
|
||
|
|
# http://svn.colorstudy.com/home/ianb/recipes/magicset.py
|
||
|
|
# including python 3 fixes for func_name => __name__ and types.ClassType => type
|
||
|
|
|
||
|
|
def magic_set(obj):
|
||
|
|
"""
|
||
|
|
Adds a function/method to an object. Uses the name of the first
|
||
|
|
argument as a hint about whether it is a method (``self``), class
|
||
|
|
method (``cls`` or ``klass``), or static method (anything else).
|
||
|
|
Works on both instances and classes.
|
||
|
|
|
||
|
|
>>> class color:
|
||
|
|
... def __init__(self, r, g, b):
|
||
|
|
... self.r, self.g, self.b = r, g, b
|
||
|
|
>>> c = color(0, 1, 0)
|
||
|
|
>>> c # doctest: +ELLIPSIS
|
||
|
|
<__main__.color instance at ...>
|
||
|
|
>>> @magic_set(color)
|
||
|
|
... def __repr__(self):
|
||
|
|
... return '<color %s %s %s>' % (self.r, self.g, self.b)
|
||
|
|
>>> c
|
||
|
|
<color 0 1 0>
|
||
|
|
>>> @magic_set(color)
|
||
|
|
... def red(cls):
|
||
|
|
... return cls(1, 0, 0)
|
||
|
|
>>> color.red()
|
||
|
|
<color 1 0 0>
|
||
|
|
>>> c.red()
|
||
|
|
<color 1 0 0>
|
||
|
|
>>> @magic_set(color)
|
||
|
|
... def name():
|
||
|
|
... return 'color'
|
||
|
|
>>> color.name()
|
||
|
|
'color'
|
||
|
|
>>> @magic_set(c)
|
||
|
|
... def name(self):
|
||
|
|
... return 'red'
|
||
|
|
>>> c.name()
|
||
|
|
'red'
|
||
|
|
>>> @magic_set(c)
|
||
|
|
... def name(cls):
|
||
|
|
... return cls.__name__
|
||
|
|
>>> c.name()
|
||
|
|
'color'
|
||
|
|
>>> @magic_set(c)
|
||
|
|
... def pr(obj):
|
||
|
|
... print obj
|
||
|
|
>>> c.pr(1)
|
||
|
|
1
|
||
|
|
"""
|
||
|
|
def decorator(func):
|
||
|
|
is_class = isinstance(obj, six.class_types)
|
||
|
|
args, varargs, varkw, defaults = inspect.getargspec(func)
|
||
|
|
if not args or args[0] not in ('self', 'cls', 'klass'):
|
||
|
|
# Static function/method
|
||
|
|
if is_class:
|
||
|
|
replacement = staticmethod(func)
|
||
|
|
else:
|
||
|
|
replacement = func
|
||
|
|
elif args[0] == 'self':
|
||
|
|
if is_class:
|
||
|
|
replacement = func
|
||
|
|
else:
|
||
|
|
def replacement(*args, **kw):
|
||
|
|
return func(obj, *args, **kw)
|
||
|
|
try:
|
||
|
|
replacement.__name__ = func.__name__
|
||
|
|
except:
|
||
|
|
pass
|
||
|
|
else:
|
||
|
|
if is_class:
|
||
|
|
replacement = classmethod(func)
|
||
|
|
else:
|
||
|
|
def replacement(*args, **kw):
|
||
|
|
return func(obj.__class__, *args, **kw)
|
||
|
|
try:
|
||
|
|
replacement.__name__ = func.__name__
|
||
|
|
except:
|
||
|
|
pass
|
||
|
|
setattr(obj, func.__name__, replacement)
|
||
|
|
return replacement
|
||
|
|
return decorator
|
||
|
|
|
||
|
|
if __name__ == '__main__':
|
||
|
|
import doctest
|
||
|
|
doctest.testmod()
|
||
|
|
|
||
|
|
|