view roundup/anypy/cmp_.py @ 5543:bc3e00a3d24b

MySQL backend fixes for Python 3. With Python 2, text sent to and from MySQL is treated as bytes in Python. The database may be recorded by MySQL as having some other encoding (latin1 being the default in some MySQL versions - Roundup does not set an encoding explicitly, unlike in back_postgresql), but as long as MySQL's notion of the connection encoding agrees with its notion of the database encoding, no conversions actually take place and the bytes are stored and returned as-is. With Python 3, text sent to and from MySQL is treated as Python Unicode strings. When the database and connection encoding is latin1, that means the bytes stored in the database under Python 2 are interpreted as latin1 and converted from that to Unicode, producing incorrect results for any non-ASCII characters; furthermore, if trying to store new non-ASCII data in the database under Python 3, any non-latin1 characters produce errors. This patch arranges for both the connection and database character sets to be UTF-8 when using Python 3, and documents a need to export and import the database when moving from Python 2 to Python 3 with this backend.
author Joseph Myers <jsm@polyomino.org.uk>
date Sun, 16 Sep 2018 16:19:20 +0000
parents 9a09719b0d8e
children 142553f58694
line wrap: on
line source

try:
    None < 0
    def NoneAndDictComparable(v):
        return v
except TypeError:
    # comparator to allow comparisons against None and dict
    # comparisons (these were allowed in Python 2, but aren't allowed
    # in Python 3 any more)
    class NoneAndDictComparable(object):
        def __init__(self, value):
            self.value = value

        def __cmp__(self, other):
            if not isinstance(other, self.__class__):
                raise TypeError('not comparable')

            if self.value == other.value:
                return 0

            elif self.value is None:
                return -1

            elif other.value is None:
                return 1

            elif type(self.value) == tuple and type(other.value) == tuple:
                for lhs, rhs in zip(self.value, other.value):
                    lhsCmp = NoneAndDictComparable(lhs)
                    rhsCmp = NoneAndDictComparable(rhs)
                    result = lhsCmp.__cmp__(rhsCmp)
                    if result != 0:
                        return result

                return len(self.value) - len(other.value)

            elif type(self.value) == dict and type(other.value) == dict:
                diff = len(self.value) - len(other.value)
                if diff == 0:
                    lhsItems = tuple(sorted(self.value.items(),
                                            key=NoneAndDictComparable))
                    rhsItems = tuple(sorted(other.value.items(),
                                            key=NoneAndDictComparable))
                    return -1 if NoneAndDictComparable(lhsItems) < NoneAndDictComparable(rhsItems) else 1
                else:
                    return diff

            elif self.value < other.value:
                return -1

            else:
                return 1

        def __eq__(self, other):
            return self.__cmp__(other) == 0
        def __ne__(self, other):
            return self.__cmp__(other) != 0
        def __lt__(self, other):
            return self.__cmp__(other) < 0
        def __le__(self, other):
            return self.__cmp__(other) <= 0
        def __ge__(self, other):
            return self.__cmp__(other) >= 0
        def __gt__(self, other):
            return self.__cmp__(other) > 0

def _test():
    Comp = NoneAndDictComparable

    assert Comp(None) < Comp(0)
    assert Comp(None) < Comp('')
    assert Comp(None) < Comp({})
    assert Comp((0, None)) < Comp((0, 0))
    assert not Comp(0) < Comp(None)
    assert not Comp('') < Comp(None)
    assert not Comp({}) < Comp(None)
    assert not Comp((0, 0)) < Comp((0, None))

    assert Comp((0, 0)) < Comp((0, 0, None))
    assert Comp((0, None, None)) < Comp((0, 0, 0))

    assert Comp(0) < Comp(1)
    assert Comp(1) > Comp(0)
    assert not Comp(1) < Comp(0)
    assert not Comp(0) > Comp(0)

    assert Comp({ 0: None }) < Comp({ 0: 0 })
    assert Comp({ 0: 0 }) < Comp({ 0: 1 })

    assert Comp({ 0: 0 }) == Comp({ 0: 0 })
    assert Comp({ 0: 0 }) != Comp({ 0: 1 })
    assert Comp({ 0: 0, 1: 1 }) > Comp({ 0: 1 })
    assert Comp({ 0: 0, 1: 1 }) < Comp({ 0: 0, 2: 2 })

if __name__ == '__main__':
    _test()

Roundup Issue Tracker: http://roundup-tracker.org/