decorators.py
68 lines
| 1.6 KiB
| text/x-python
|
PythonLexer
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r6266 | """ | ||
doc_inherit decorator | ||||
Usage: | ||||
class Foo(object): | ||||
def foo(self): | ||||
"Frobber" | ||||
pass | ||||
class Bar(Foo): | ||||
@doc_inherit | ||||
def foo(self): | ||||
pass | ||||
Now, Bar.foo.__doc__ == Bar().foo.__doc__ == Foo.foo.__doc__ == "Frobber" | ||||
See: http://stackoverflow.com/questions/2025562/inherit-docstrings-in-python-class-inheritance | ||||
""" | ||||
from functools import wraps | ||||
class DocInherit(object): | ||||
""" | ||||
Docstring inheriting method descriptor | ||||
The class itself is also used as a decorator | ||||
""" | ||||
def __init__(self, mthd): | ||||
self.mthd = mthd | ||||
self.name = mthd.__name__ | ||||
def __get__(self, obj, cls): | ||||
if obj: | ||||
return self.get_with_inst(obj, cls) | ||||
else: | ||||
return self.get_no_inst(cls) | ||||
def get_with_inst(self, obj, cls): | ||||
overridden = getattr(super(cls, obj), self.name, None) | ||||
@wraps(self.mthd, assigned=('__name__', '__module__')) | ||||
def f(*args, **kwargs): | ||||
return self.mthd(obj, *args, **kwargs) | ||||
return self.use_parent_doc(f, overridden) | ||||
def get_no_inst(self, cls): | ||||
for parent in cls.__mro__[1:]: | ||||
overridden = getattr(parent, self.name, None) | ||||
if overridden: break | ||||
@wraps(self.mthd, assigned=('__name__', '__module__')) | ||||
def f(*args, **kwargs): | ||||
return self.mthd(*args, **kwargs) | ||||
return self.use_parent_doc(f, overridden) | ||||
def use_parent_doc(self, func, source): | ||||
if source is None: | ||||
raise NameError, ("Can't find '%s' in parents" % self.name) | ||||
func.__doc__ = source.__doc__ | ||||
return func | ||||
doc_inherit = DocInherit | ||||