pylint/checkers/format.py
def _check_keyword_parentheses(self, tokens, start):
        """Check that there are not unnecessary parens after a keyword.

        Parens are unnecessary if there is exactly one balanced outer pair on a
        line, and it is followed by a colon, and contains no commas (i.e. is not a
        tuple).

        Args:
        tokens: list of Tokens; the entire list of Tokens.
        start: int; the position of the keyword in the token list.
        """
        # If the next token is not a paren, we're fine.
        if self._inside_brackets(":") and tokens[start][1] == "for":
            self._pop_token()
        if tokens[start + 1][1] != "(":
            return

        found_and_or = False
        depth = 0
        keyword_token = str(tokens[start][1])
        line_num = tokens[start][2][0]

        for i in range(start, len(tokens) - 1):
            token = tokens[i]

            # If we hit a newline, then assume any parens were for continuation.
            if token[0] == tokenize.NL:
                return

            if token[1] == "(":
                depth += 1
            elif token[1] == ")":
                depth -= 1
                if depth:
                    continue
                # ')' can't happen after if (foo), since it would be a syntax error.
                if tokens[i + 1][1] in (":", ")", "]", "}", "in") or tokens[i + 1][
                    0
                ] in (tokenize.NEWLINE, tokenize.ENDMARKER, tokenize.COMMENT):
                    # The empty tuple () is always accepted.
                    if i == start + 2:
                        return
                    if keyword_token == "not":
                        if not found_and_or:
                            self.add_message(
                                "superfluous-parens", line=line_num, args=keyword_token
                            )
                    elif keyword_token in ("return", "yield"):
                        self.add_message(
                            "superfluous-parens", line=line_num, args=keyword_token
                        )
                    elif keyword_token not in self._keywords_with_parens:
                        if not found_and_or:
                            self.add_message(
                                "superfluous-parens", line=line_num, args=keyword_token
                            )
                return
            elif depth == 1:
                # This is a tuple, which is always acceptable.
                if token[1] == ",":
                    return
                # 'and' and 'or' are the only boolean operators with lower precedence
                # than 'not', so parens are only required when they are found.
                if token[1] in ("and", "or"):
                    found_and_or = True
                # A yield inside an expression must always be in parentheses,
                # quit early without error.
                elif token[1] == "yield":
                    return
                # A generator expression always has a 'for' token in it, and
                # the 'for' token is only legal inside parens when it is in a
                # generator expression.  The parens are necessary here, so bail
                # without an error.
                elif token[1] == "for":
                    return
def _check_keyword_parentheses(self, tokens, start):
        """Check that there are not unnecessary parens after a keyword.

        Parens are unnecessary if there is exactly one balanced outer pair on a
        line, and it is followed by a colon, and contains no commas (i.e. is not a
        tuple).

        Args:
        tokens: list of Tokens; the entire list of Tokens.
        start: int; the position of the keyword in the token list.
        """
        # If the next token is not a paren, we're fine.
        if self._inside_brackets(":") and tokens[start][1] == "for":
            self._pop_token()
        if tokens[start + 1][1] != "(":
            return

        found_and_or = False
        depth = 0
        keyword_token = str(tokens[start][1])
        line_num = tokens[start][2][0]

        for i in range(start, len(tokens) - 1):
            token = tokens[i]

            # If we hit a newline, then assume any parens were for continuation.
            if token[0] == tokenize.NL:
                return

            if token[1] == "(":
                depth += 1
            elif token[1] == ")":
                depth -= 1
                if depth:
                    continue
                # ')' can't happen after if (foo), since it would be a syntax error.
                if tokens[i + 1][1] in (":", ")", "]", "}", "in") or tokens[i + 1][
                    0
                ] in (tokenize.NEWLINE, tokenize.ENDMARKER, tokenize.COMMENT):
                    # The empty tuple () is always accepted.
                    if i == start + 2:
                        return
                    if keyword_token == "not":
                        if not found_and_or:
                            self.add_message(
                                "superfluous-parens", line=line_num, args=keyword_token
                            )
                    elif keyword_token in ("return", "yield"):
                        self.add_message(
                            "superfluous-parens", line=line_num, args=keyword_token
                        )
                    elif keyword_token not in self._keywords_with_parens:
                        if not found_and_or:
                            self.add_message(
                                "superfluous-parens", line=line_num, args=keyword_token
                            )
                return
            elif depth == 1:
                # This is a tuple, which is always acceptable.
                if token[1] == ",":
                    return
                # 'and' and 'or' are the only boolean operators with lower precedence
                # than 'not', so parens are only required when they are found.
                if token[1] in ("and", "or"):
                    found_and_or = True
                # A yield inside an expression must always be in parentheses,
                # quit early without error.
                elif token[1] == "yield":
                    return
                # A generator expression always has a 'for' token in it, and
                # the 'for' token is only legal inside parens when it is in a
                # generator expression.  The parens are necessary here, so bail
                # without an error.
                elif token[1] == "for":
                    return
Check that there are not unnecessary parens after a keyword.

        Parens are unnecessary if there is exactly one balanced outer pair on a
        line, and it is followed by a colon, and contains no commas (i.e. is not a
        tuple).

        Args:
        tokens: list of Tokens; the entire list of Tokens.
        start: int; the position of the keyword in the token list.