| msg147181 - (view) |
Author: Florent Xicluna (flox) *  |
Date: 2011-11-06 20:22 |
| The UnicodeWarning is raised on some dict or set operations. It is not very helpful, and sometimes annoying. And it is somewhat inconsistent. # ** warning not raised ** $ python2.7 -c "print u'd\xe9' in {'foo', 'bar'}" False $ python2.7 -c "print 'd\xe9' in {u'foo', u'bar'}" False $ python2.7 -c "print 'd\xc3\xa9' in {u'foo', u'd\xe9'}" False # ** warning raised ** $ python2.7 -c "print 'd\xe9' in {u'foo', u'd\xe9'}" -c:1: UnicodeWarning: Unicode equal comparison failed to convert both arguments to Unicode - interpreting them as being unequal False $ python2.7 -c "print u'd\xe9' in {'foo', 'd\xe9'}" -c:1: UnicodeWarning: Unicode equal comparison failed to convert both arguments to Unicode - interpreting them as being unequal False |
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| msg147183 - (view) |
Author: Florent Xicluna (flox) * |
Date: 2011-11-06 20:46 |
| Similar expressions where the warning is raised or not (depending on "latin-1" comparison): $ python2.7 -c "print u'd\xe9' in {'foo', 'd\xe9r'}" False $ python2.7 -c "print u'd\xe9' in {'foo', 'd\xe9'}" -c:1: UnicodeWarning: Unicode equal comparison failed to convert both arguments to Unicode - interpreting them as being unequal False $ python2.7 -c "print 'd\xe9r' in {u'foo', u'd\xe9'}" False $ python2.7 -c "print 'd\xe9' in {u'foo', u'd\xe9'}" -c:1: UnicodeWarning: Unicode equal comparison failed to convert both arguments to Unicode - interpreting them as being unequal False |
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| msg147187 - (view) |
Author: Martin v. Löwis (loewis) * |
Date: 2011-11-06 21:23 |
| I fail to see the issue. What exactly is the problem with the warning? It looks all consistent and helpful to me. |
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| msg147188 - (view) |
Author: Florent Xicluna (flox) * |
Date: 2011-11-06 21:43 |
| Often sequences or sets have heterogeneous keys, mixing and , and in this case there's no easy way to work with them without raising this UnicodeWarning. The "logging" module is such an example. Of course it is only a warning, not a strong annoyance. |
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| msg147191 - (view) |
Author: Martin v. Löwis (loewis) * |
Date: 2011-11-06 22:46 |
| > Often sequences or sets have heterogeneous keys, mixing and > , and in this case there's no easy way to work with them > without raising this UnicodeWarning. That's a bug in the application. You must not mix byte strings and unicode strings as dictionary keys. Whether or not the warning is produced: the behavior would still be fairly unpredictable, and vary with Python versions. > Of course it is only a warning, not a strong annoyance. This warning is deliberate. It tells the developer that something is broken about this application. |
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| msg147310 - (view) |
Author: Florent Xicluna (flox) * |
Date: 2011-11-08 17:13 |
| Then we'll live with it, or work around when it's possible. For the purists, hopefully we have Python 3 which allows to mix bytes and strings in a set(). |
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