def _list_checkers(self):
        """
        Print information about checkers and their external tools.

        Currently only works properly on systems with the `which` tool
        available.
        """
        classes = set()
        for checker_group in checkers.checkers.itervalues():
            for checker in checker_group:
                classes.add(checker)

        max_width = 0
        for clazz in classes:
            max_width = max(max_width, len(clazz.tool), len(clazz.__name__))

        for clazz in sorted(classes):
            status, _ = commands.getstatusoutput(clazz.tool % 'which %s')
            result = 'missing' if status else 'installed'
            version = '' if status else clazz.get_version()
            print '%s%s%s%s' % (
                clazz.__name__.ljust(max_width + 1),
                clazz.tool.ljust(max_width + 1),
                result.ljust(max_width + 1),
                version,
            )
dataset/ETHPy150Open jenanwise/codequality/codequality/main.py/CodeQuality._list_checkers/swapped operands of `%`