| msg274210 - (view) |
Author: Ondřej Medek (Ondřej Medek) |
Date: 2016-09-02 08:33 |
| The logging.getLevelName contains code: return _levelToName.get(level, _nameToLevel.get(level, ("Level %s" % level))) I am still a Python beginner, but I think the most of the times the _nameToLevel.get is called unnecessarily. IMHO the code should be return _levelToName.get(level, (_nameToLevel.get(level, ("Level %s" % level)))) or maybe better a classic if then style: result = _levelToName.get(level) if result is None: result = _nameToLevel.get(level, ("Level %s" % level)) return result Since this function is called every time the LogRecord is created, I think it should be microoptimized. |
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| msg274211 - (view) |
Author: Xiang Zhang (xiang.zhang) *  |
Date: 2016-09-02 08:46 |
| What's the meaning of the first method? |
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| msg274215 - (view) |
Author: Ondřej Medek (Ondřej Medek) |
Date: 2016-09-02 09:03 |
| Which 'first' method do you mean? logging.getLevelName() converts level (int) to level name (str). But due to the backward compatibility is also converts level name (str) to level (int). |
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| msg274216 - (view) |
Author: Xiang Zhang (xiang.zhang) * |
Date: 2016-09-02 09:06 |
| No, I mean this method you propose: return _levelToName.get(level, (_nameToLevel.get(level, ("Level %s" % level)))) I cannot see any difference with the original code, except parentheses. |
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| msg274218 - (view) |
Author: Ondřej Medek (Ondřej Medek) |
Date: 2016-09-02 09:11 |
| That's probably my lack of Python knowledge. I have though that parentheses in ("Level %s" % level) cause lazy evaluation. If not, then this code has to be optimized by if-then, too. |
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| msg274247 - (view) |
Author: R. David Murray (r.david.murray) * |
Date: 2016-09-02 15:03 |
| Parens do not cause lazy evaluation unless what is parenthesized is a generator comprehension. An expanded if solution is the correct one. If Vinay prefers a one liner, I think you could also write: _levelToName.get(level) or _nameToLevel.get(level) or ("Level %s" % level) Because we know we get back either a True string or None, I don't think there's any ambiguity there. |
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| msg274302 - (view) |
Author: Roundup Robot (python-dev)  |
Date: 2016-09-03 15:55 |
| New changeset 0986401d0733 by Vinay Sajip in branch 'default': Fixes #27937: optimise code used in all logging calls. https://hg.python.org/cpython/rev/0986401d0733 New changeset e4b6faf22e8d by Vinay Sajip in branch '3.5': Fixes #27937: optimise code used in all logging calls. https://hg.python.org/cpython/rev/e4b6faf22e8d New changeset 773c9401735f by Vinay Sajip in branch 'default': Closes #27937: Merge fix from 3.5. https://hg.python.org/cpython/rev/773c9401735f |
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