Mike Krell wrote:
> Peter Otten <__peter__ at web.de> wrote in
> news:ehggfk$60i$00$1 at news.t-online.com:
>>> I get
>>>> np: "overridden __str__: c:/mbk/test"
>> str(np): "overridden __str__: c:/mbk/test"
>> overridden __str__: overridden __str__: c:/mbk/test/appendtest
>> Hmmm. I guess you're not running under windows, since normpath()
> converts / to \ on windows. I wonder if that's part of the problem.
>>>> Are you using the latest version of the path module?
>> My path.py says it's 2.1, which is the latest according to the site.
>> Older versions
>> implied a Path() call in the __div__() operator which would explain at
>> least the output you get for
>>>> print np / 'appendtest'
>> You've lost me here. What do you mean about "implied a Path() call"?
> Here is the definition of __div__ from path.py:
>> '''
> # The / operator joins paths.
> def __div__(self, rel):
> """ fp.__div__(rel) == fp / rel == fp.joinpath(rel)
>> Join two path components, adding a separator character if
> needed.
> """
> return self.__class__(os.path.join(self, rel))
> '''
>From http://www.jorendorff.com/articles/python/path/changes.html:
"""
This page describes recent changes to the Python path module.
2.1
[...]
Better support for subclassing path. All methods that returned path objects
now respect subclassing.
Before: type(PathSubclass(s).parent) is path
Now: type(PathSubclass(s).parent) is PathSubclass
"""
So my assumption was that you are using a pre-2.1 version of path.
I suggest that you double-check that by inserting a
print path.__version__
into the code showing the odd behaviour before you start looking for more
exotic causes.
> I still don't understand the TypeError in the delegation case.
For newstyle classes
a = A()
a / 42 # or any other operation implemented via __xxx__()
(unlike a.__div__) will only look into the class for a __div__() special
method and ignore methods defined in the instance or via the __getattr__()
mechanism.
For delegation to work you need (untested)
class NormPath(object):
def __div__(self, other):
return self.__class__(self._path / other)
# ...
Peter
