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.
106 lines
4.7 KiB
106 lines
4.7 KiB
"""functools.py - Tools for working with functions and callable objects
|
|
"""
|
|
# Python module wrapper for _functools C module
|
|
# to allow utilities written in Python to be added
|
|
# to the functools module.
|
|
# Written by Nick Coghlan <ncoghlan at gmail.com>
|
|
# Copyright (C) 2006 Python Software Foundation.
|
|
# See C source code for _functools credits/copyright
|
|
|
|
from _functools import partial, reduce
|
|
|
|
# update_wrapper() and wraps() are tools to help write
|
|
# wrapper functions that can handle naive introspection
|
|
|
|
WRAPPER_ASSIGNMENTS = ('__module__', '__name__', '__doc__')
|
|
WRAPPER_UPDATES = ('__dict__',)
|
|
def update_wrapper(wrapper,
|
|
wrapped,
|
|
assigned = WRAPPER_ASSIGNMENTS,
|
|
updated = WRAPPER_UPDATES):
|
|
"""Update a wrapper function to look like the wrapped function
|
|
|
|
wrapper is the function to be updated
|
|
wrapped is the original function
|
|
assigned is a tuple naming the attributes assigned directly
|
|
from the wrapped function to the wrapper function (defaults to
|
|
functools.WRAPPER_ASSIGNMENTS)
|
|
updated is a tuple naming the attributes of the wrapper that
|
|
are updated with the corresponding attribute from the wrapped
|
|
function (defaults to functools.WRAPPER_UPDATES)
|
|
"""
|
|
for attr in assigned:
|
|
setattr(wrapper, attr, getattr(wrapped, attr))
|
|
for attr in updated:
|
|
getattr(wrapper, attr).update(getattr(wrapped, attr, {}))
|
|
# Return the wrapper so this can be used as a decorator via partial()
|
|
return wrapper
|
|
|
|
def wraps(wrapped,
|
|
assigned = WRAPPER_ASSIGNMENTS,
|
|
updated = WRAPPER_UPDATES):
|
|
"""Decorator factory to apply update_wrapper() to a wrapper function
|
|
|
|
Returns a decorator that invokes update_wrapper() with the decorated
|
|
function as the wrapper argument and the arguments to wraps() as the
|
|
remaining arguments. Default arguments are as for update_wrapper().
|
|
This is a convenience function to simplify applying partial() to
|
|
update_wrapper().
|
|
"""
|
|
return partial(update_wrapper, wrapped=wrapped,
|
|
assigned=assigned, updated=updated)
|
|
|
|
def total_ordering(cls):
|
|
"""Class decorator that fills in missing ordering methods"""
|
|
convert = {
|
|
'__lt__': [('__gt__', lambda self, other: not (self < other or self == other)),
|
|
('__le__', lambda self, other: self < other or self == other),
|
|
('__ne__', lambda self, other: not self == other),
|
|
('__ge__', lambda self, other: not self < other)],
|
|
'__le__': [('__ge__', lambda self, other: not self <= other or self == other),
|
|
('__lt__', lambda self, other: self <= other and not self == other),
|
|
('__ne__', lambda self, other: not self == other),
|
|
('__gt__', lambda self, other: not self <= other)],
|
|
'__gt__': [('__lt__', lambda self, other: not (self > other or self == other)),
|
|
('__ge__', lambda self, other: self > other or self == other),
|
|
('__ne__', lambda self, other: not self == other),
|
|
('__le__', lambda self, other: not self > other)],
|
|
'__ge__': [('__le__', lambda self, other: (not self >= other) or self == other),
|
|
('__gt__', lambda self, other: self >= other and not self == other),
|
|
('__ne__', lambda self, other: not self == other),
|
|
('__lt__', lambda self, other: not self >= other)]
|
|
}
|
|
defined_methods = set(dir(cls))
|
|
roots = defined_methods & set(convert)
|
|
if not roots:
|
|
raise ValueError('must define at least one ordering operation: < > <= >=')
|
|
root = max(roots) # prefer __lt__ to __le__ to __gt__ to __ge__
|
|
for opname, opfunc in convert[root]:
|
|
if opname not in defined_methods:
|
|
opfunc.__name__ = opname
|
|
opfunc.__doc__ = getattr(int, opname).__doc__
|
|
setattr(cls, opname, opfunc)
|
|
return cls
|
|
|
|
def cmp_to_key(mycmp):
|
|
"""Convert a cmp= function into a key= function"""
|
|
class K(object):
|
|
__slots__ = ['obj']
|
|
def __init__(self, obj, *args):
|
|
self.obj = obj
|
|
def __lt__(self, other):
|
|
return mycmp(self.obj, other.obj) < 0
|
|
def __gt__(self, other):
|
|
return mycmp(self.obj, other.obj) > 0
|
|
def __eq__(self, other):
|
|
return mycmp(self.obj, other.obj) == 0
|
|
def __le__(self, other):
|
|
return mycmp(self.obj, other.obj) <= 0
|
|
def __ge__(self, other):
|
|
return mycmp(self.obj, other.obj) >= 0
|
|
def __ne__(self, other):
|
|
return mycmp(self.obj, other.obj) != 0
|
|
def __hash__(self):
|
|
raise TypeError('hash not implemented')
|
|
return K
|