If ' [ ' opening bracket , push it into character stack .
elif ( Str [ i ] == ' [ ' ) : NEW_LINE INDENT if ( Str [ i - 1 ] >= '0' and Str [ i - 1 ] <= '9' ) : NEW_LINE INDENT stringstack . append ( Str [ i ] ) NEW_LINE DEDENT else : NEW_LINE INDENT stringstack . append ( Str [ i ] ) NEW_LINE integerstack . append ( 1 ) NEW_LINE DEDENT DEDENT else : NEW_LINE INDENT stringstack . append ( Str [ i ] ) NEW_LINE DEDENT i += 1 NEW_LINE