"""Formatter extension to support sliced strings."""

import string


class SliceFormatter(string.Formatter):
    """Class extending string formatter by slice support."""

    def get_value(self, key, args, kwargs):
        """Called by string.Formatter for each format key found in the format string.

        Args:
            key (str): Format key string (possibly containing slice)
            args (list): Format values list tuple
            kwargs (dict): Format values dictionary

        Returns:
            string: Formatted key or Missing word
        """
        if '(' in key and ')' in key:
            try:
                key, indexes = key.rstrip(')').split('(')
                indexes = list(map(int, indexes.split(',')))
                if (indexes[1] < indexes[0]):
                    indexes[1] += indexes[0]
                if key.isdigit():
                    return args[int(key)][slice(*indexes)]
                return kwargs[key][slice(*indexes)]
            except KeyError:
                return kwargs.get(key, 'Missing')
        return super(SliceFormatter, self).get_value(key, args, kwargs)