On Thu, Jun 9, 2016 at 5:07 AM Nagy László Zsolt <gand...@shopzeus.com>
wrote:
> I would like to create a collections.UserList subclass that can notify
> others when the list is mutated.
>
Why not subclass MutableSequence instead? The ABC will tell you which
methods to override (the abstract ones). The mixin methods rely on those
overrides.
from collections.abc import MutableSequence
def noisy(message):
def decorator(func):
def wrapper(*args, **kwargs):
print(message)
return func(*args, **kwargs)
return wrapper
return decorator
class NoisyList(MutableSequence):
def __init__(self, *args, **kwargs):
self.contents = list(*args, **kwargs)
def __getitem__(self, index):
return self.contents[index]
def __len__(self):
return len(self.contents)
@noisy('set')
def __setitem__(self, index, value):
self.contents[index] = value
@noisy('del')
def __delitem__(self, index):
del self.contents[index]
@noisy('insert')
def insert(self, index, value):
self.contents.insert(index, value)
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