def _detab(self, text):
        r"""Remove (leading?) tabs from a file.

            >>> m = Markdown()
            >>> m._detab("\tfoo")
            '    foo'
            >>> m._detab("  \tfoo")
            '    foo'
            >>> m._detab("\t  foo")
            '      foo'
            >>> m._detab("  foo")
            '  foo'
            >>> m._detab("  foo\n\tbar\tblam")
            '  foo\n    bar blam'
        """
        if text not in '\t':
            return text
        return self._detab_re.subn(self._detab_sub, text)[0]

    # I broke out the html5 tags here and add them to _block_tags_a and
    # _block_tags_b.  This way html5 tags are easy to keep track of.
dataset/ETHPy150Open an0/Letterpress/code/markdown2/lib/markdown2.py/Markdown._detab/swapped operands of `not in`