New submission from Rob Malouf: Several collections.Counter methods return Counter objects, which is leads to wrong or at least confusing behavior when Counter is subclassed. For example, nltk.FreqDist is a subclass of Counter:
>>> x = nltk.FreqDist(['a','a','b','b','b']) >>> y = nltk.FreqDist(['b','b','b','b','b']) >>> z = x + y >>> z.__class__ <class 'collections.Counter'> This applies to __add__(), __sub__(), __or__(), __and__(), __pos__(), and __neg__(). In contrast, the copy() method does (what I think is) the right thing: >>> x.copy().__class__ <class 'nltk.probability.FreqDist'> ---------- components: Library (Lib) messages: 253930 nosy: rmalouf priority: normal severity: normal status: open title: collections.Counter methods return Counter objects type: behavior versions: Python 3.5 _______________________________________ Python tracker <rep...@bugs.python.org> <http://bugs.python.org/issue25535> _______________________________________ _______________________________________________ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
