Method assertSequenceEqual

Lib/unittest/case.py:1016–1113

An equality assertion for ordered sequences (like lists and tuples). For the purposes of this function, a valid ordered sequence type is one which can be indexed, has a length, and has an equality operator. Args: seq1: The first sequence to compare.

(self, seq1, seq2, msg=None, seq_type=None)

        raise self.failureException(msg)

    def assertSequenceEqual(self, seq1, seq2, msg=None, seq_type=None):
        """An equality assertion for ordered sequences (like lists and tuples).

        For the purposes of this function, a valid ordered sequence type is one
        which can be indexed, has a length, and has an equality operator.

        Args:
            seq1: The first sequence to compare.
            seq2: The second sequence to compare.
            seq_type: The expected datatype of the sequences, or None if no
                    datatype should be enforced.
            msg: Optional message to use on failure instead of a list of
                    differences.
        """
        if seq_type is not None:
            seq_type_name = seq_type.__name__
            if not isinstance(seq1, seq_type):
                raise self.failureException('First sequence is not a %s: %s'
                                        % (seq_type_name, safe_repr(seq1)))
            if not isinstance(seq2, seq_type):
                raise self.failureException('Second sequence is not a %s: %s'
                                        % (seq_type_name, safe_repr(seq2)))
        else:
            seq_type_name = "sequence"

        differing = None
        try:
            len1 = len(seq1)
        except (TypeError, NotImplementedError):
            differing = 'First %s has no length.    Non-sequence?' % (
                    seq_type_name)

        if differing is None:
            try:
                len2 = len(seq2)
            except (TypeError, NotImplementedError):
                differing = 'Second %s has no length.    Non-sequence?' % (
                        seq_type_name)

        if differing is None:
            if seq1 == seq2:
                return

            differing = '%ss differ: %s != %s\n' % (
                    (seq_type_name.capitalize(),) +
                    _common_shorten_repr(seq1, seq2))

            for i in range(min(len1, len2)):
                try:
                    item1 = seq1[i]
                except (TypeError, IndexError, NotImplementedError):
                    differing += ('\nUnable to index element %d of first %s\n' %
                                 (i, seq_type_name))
                    break

                try:
                    item2 = seq2[i]
                except (TypeError, IndexError, NotImplementedError):