Re: unorderable error: less ok, equal ok, less-or-equal gives unorderable error!
Ethan Furman wrote: On 06/30/2014 12:34 PM, Peter Otten wrote: RainyDay wrote: def __eq__(self, other): return self._loc == getattr(other, _loc, None) Note that None is not a good default when _loc is expected to be a tuple: In this case None is not being returned, but will be comparid with self._loc, so RainyDay is good there. RainyDay wrote: I'm only using None in equality comparison, it's never a default value of _loc itself, so this should be ok because it'll compare to all other object types and correctly say they're unequal. Yes, sorry. I read what I expected rather than what was there. -- https://mail.python.org/mailman/listinfo/python-list
Re: unorderable error: less ok, equal ok, less-or-equal gives unorderable error!
RainyDay wrote: Hi, in python 3.4.1, I get this surpising behaviour: l=Loc(0,0) l2=Loc(1,1) ll2 False ll2 True l=l2 Traceback (most recent call last): File stdin, line 1, in module TypeError: unorderable types: Loc() = Loc() l==l2 False ll2 or l==l2 True Loc implements both __lt__ and __eq__, which should be enough (?), These two methods should be sufficient if you use the functools.total_ordering class decorator, see https://docs.python.org/dev/library/functools.html#functools.total_ordering but even after I've added __lte__, I still have the error. There is no special method of that name; it should probably be __le__(). implementation: class Loc: def __init__(self, x, y): self._loc = x, y self.x, self.y = x, y def __eq__(self, other): return self._loc == getattr(other, _loc, None) Note that None is not a good default when _loc is expected to be a tuple: None () Traceback (most recent call last): File stdin, line 1, in module TypeError: unorderable types: NoneType() tuple() def __lt__(self, other): return self._loc other._loc - andrei -- https://mail.python.org/mailman/listinfo/python-list
Re: unorderable error: less ok, equal ok, less-or-equal gives unorderable error!
On Monday, June 30, 2014 3:34:25 PM UTC-4, Peter Otten wrote: RainyDay wrote: Hi, in python 3.4.1, I get this surpising behaviour: l=Loc(0,0) l2=Loc(1,1) ll2 False ll2 True l=l2 Traceback (most recent call last): File stdin, line 1, in module TypeError: unorderable types: Loc() = Loc() l==l2 False ll2 or l==l2 True Loc implements both __lt__ and __eq__, which should be enough (?), These two methods should be sufficient if you use the functools.total_ordering class decorator, see Thanks! I literally failed to read one more paragraph in a SO answer which referenced this decorator. I really need to start reading those paragraphs, they often provide answers... but even after I've added __lte__, I still have the error. There is no special method of that name; it should probably be __le__(). Right, I used lte in django and assumed they were consistent with python. def __eq__(self, other): return self._loc == getattr(other, _loc, None) Note that None is not a good default when _loc is expected to be a tuple: I'm only using None in equality comparison, it's never a default value of _loc itself, so this should be ok because it'll compare to all other object types and correctly say they're unequal. - andrei -- https://mail.python.org/mailman/listinfo/python-list
Re: unorderable error: less ok, equal ok, less-or-equal gives unorderable error!
On 06/30/2014 12:34 PM, Peter Otten wrote: RainyDay wrote: def __eq__(self, other): return self._loc == getattr(other, _loc, None) Note that None is not a good default when _loc is expected to be a tuple: In this case None is not being returned, but will be comparid with self._loc, so RainyDay is good there. -- ~Ethan~ -- https://mail.python.org/mailman/listinfo/python-list
