def _int_to_key(keys, index):
if isinstance(index, int):<EOL><INDENT>try:<EOL><INDENT>return keys[index]<EOL><DEDENT>except IndexError:<EOL><INDENT>raise KeyError('<STR_LIT>' % (index,))<EOL><DEDENT><DEDENT>return index<EOL>
Convert int ``index`` to the corresponding key in ``keys``