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urlparse('http:////::\\\\!!::!!++///') ParseResult(scheme='http', netloc='', path='//::\\\\!!::!!++///',

New submission from Vasiliy Faronov: There is a problem with the standard library's urlsplit and urlparse functions, in Python 2.7 (module urlparse) and 3.2+ (module urllib.parse). The documentation for these functions [1] does not explain how they behave when given an invalid URL. One could try invoking them manually and conclude that they tolerate anything thrown at them: params='', query='', fragment='')

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urlparse(os.urandom(32).decode('latin-1')) ParseResult(scheme='', netloc='', path='\x7f¼â1gdä»6\x82', params='', query='', fragment='\n\xadJ\x18+fli\x9cÛ\x9ak*ÄÅ\x02³F\x85Ç\x18')

Without studying the source code, it is impossible to know that there is a very narrow class of inputs on which they raise ValueError [2]:

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urlparse('http://[') Traceback (most recent call last): File "<stdin>", line 1, in <module> File "/usr/lib/python3.5/urllib/parse.py", line 295, in urlparse splitresult = urlsplit(url, scheme, allow_fragments) File "/usr/lib/python3.5/urllib/parse.py", line 345, in urlsplit raise ValueError("Invalid IPv6 URL") ValueError: Invalid IPv6 URL

This could be viewed as a documentation issue. But it could also be viewed as an implementation issue. Instead of raising ValueError on those square brackets, urlsplit could simply consider them *invalid* parts of an RFC 3986 reg-name, and lump them into netloc, as it already does with other *invalid* characters:

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urlparse('http://\0\0æí\n/') ParseResult(scheme='http', netloc='\x00\x00æí\n', path='/', params='', query='', fragment='')

Note that the raising behavior was introduced in Python 2.7/3.2. See also issue 8721 [3]. [1] https://docs.python.org/3/library/urllib.parse.html [2] https://github.com/python/cpython/blob/e32ec93/Lib/urllib/parse.py#L406-L408 [3] http://bugs.python.org/issue8721 ---------- assignee: docs@python components: Documentation, Library (Lib) messages: 288577 nosy: docs@python, vfaronov priority: normal severity: normal status: open title: Inconsistent/undocumented urlsplit/urlparse behavior on invalid inputs type: behavior versions: Python 2.7, Python 3.3, Python 3.4, Python 3.5, Python 3.6, Python 3.7 _______________________________________ Python tracker <report@bugs.python.org> <http://bugs.python.org/issue29651> _______________________________________