New submission from Dmitry Andreychuk: https://docs.python.org/3.4/library/functions.html?highlight=int#int The docstring for int() function has these sentences: "If x is a number, return x.__int__()." "If x is not a number or if base is given..." Unfortunately the docstring doesn't describe how the function decides if x is a number or not. After searching and experimenting I came to conclusion that it is the presence of x.__int__() method makes int() treat x as a number. But I'm not sure it's a precise requirement or just something that happens to work with current implementation. I think there should be a precise definition of what is considered to be a number there. ---------- assignee: docs@python components: Documentation messages: 219379 nosy: and, docs@python priority: normal severity: normal status: open title: int() docstring - unclear what number is versions: Python 2.7, Python 3.1, Python 3.2, Python 3.3, Python 3.4, Python 3.5 _______________________________________ Python tracker <report@bugs.python.org> <http://bugs.python.org/issue21611> _______________________________________