Feature Requests item #1155485, was opened at 2005-03-02 23:48 Message generated for change (Comment added) made by felixlee You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=355470&aid=1155485&group_id=5470
Category: Python Interpreter Core Group: None Status: Open Resolution: None Priority: 5 Submitted By: Felix Lee (felixlee) Assigned to: Nobody/Anonymous (nobody) Summary: file() on a file Initial Comment: it would be nice if file(f) worked when f is already a file, either by returning f or by constructing a new file that refers to the same thing. that would make it easy to write functions that can take either a file or a filename as an argument, like so: def p(f): print list(file(f)) which is kind of like using int() as a cast operation. ---------------------------------------------------------------------- >Comment By: Felix Lee (felixlee) Date: 2005-03-14 20:47 Message: Logged In: YES user_id=77867 that argument also works against str() and list(). it's not obvious whether str(s) and list(v) should return itself, a proxy, or a copy, and they're all useful in different situations. I don't think anyone would argue that the ambiguity means those should be undefined. I think file(f) is similar. it has a few more issues because files are special, but I think picking a reasonable behavior for file(f) would simplify some programming. returning a dup is probably the least surprising in most situations, because of f.close(). ---------------------------------------------------------------------- Comment By: Martin v. Löwis (loewis) Date: 2005-03-13 22:53 Message: Logged In: YES user_id=21627 It's not at all obvious what this should do. Three alternatives come to mind: 1. return f 2. return a wrapper object which delegates all calls 3. return a new file object, which is dup(2)'ed from the original one. Either of them might be meaningful in some context, and they are mutually incompatible. In the face of ambiguity, refuse the temptation to guess, so I'm -1. ---------------------------------------------------------------------- You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=355470&aid=1155485&group_id=5470 _______________________________________________ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com