pylint/checkers/logging.py
def _check_format_string(self, node, format_arg):
        """Checks that format string tokens match the supplied arguments.

        Args:
          node (astroid.node_classes.NodeNG): AST node to be checked.
          format_arg (int): Index of the format string in the node arguments.
        """
        num_args = _count_supplied_tokens(node.args[format_arg + 1 :])
        if not num_args:
            # If no args were supplied the string is not interpolated and can contain
            # formatting characters - it's used verbatim. Don't check any further.
            return
        format_string = node.args[format_arg].value
        if not isinstance(format_string, str):
            # If the log format is constant non-string (e.g. logging.debug(5)),
            # ensure there are no arguments.
            required_num_args = 0
        else:
            try:
                if self._format_style == "old":
                    keyword_args, required_num_args, _, _ = utils.parse_format_string(
                        format_string
                    )
                    if keyword_args:
                        # Keyword checking on logging strings is complicated by
                        # special keywords - out of scope.
                        return
                elif self._format_style == "new":
                    keyword_arguments, implicit_pos_args, explicit_pos_args = utils.parse_format_method_string(
                        format_string
                    )

                    keyword_args_cnt = len(
                        set(k for k, l in keyword_arguments if not isinstance(k, int))
                    )
                    required_num_args = (
                        keyword_args_cnt + implicit_pos_args + explicit_pos_args
                    )
            except utils.UnsupportedFormatCharacter as ex:
                char = format_string[ex.index]
                self.add_message(
                    "logging-unsupported-format",
                    node=node,
                    args=(char, ord(char), ex.index),
                )
                return
            except utils.IncompleteFormatString:
                self.add_message("logging-format-truncated", node=node)
                return
        if num_args > required_num_args:
            self.add_message("logging-too-many-args", node=node)
        elif num_args < required_num_args:
            self.add_message("logging-too-few-args", node=node)
def _check_format_string(self, node, format_arg):
        """Checks that format string tokens match the supplied arguments.

        Args:
          node (astroid.node_classes.NodeNG): AST node to be checked.
          format_arg (int): Index of the format string in the node arguments.
        """
        num_args = _count_supplied_tokens(node.args[format_arg + 1 :])
        if not num_args:
            # If no args were supplied the string is not interpolated and can contain
            # formatting characters - it's used verbatim. Don't check any further.
            return
        format_string = node.args[format_arg].value
        if not isinstance(format_string, str):
            # If the log format is constant non-string (e.g. logging.debug(5)),
            # ensure there are no arguments.
            required_num_args = 0
        else:
            try:
                if self._format_style == "old":
                    keyword_args, required_num_args, _, _ = utils.parse_format_string(
                        format_string
                    )
                    if keyword_args:
                        # Keyword checking on logging strings is complicated by
                        # special keywords - out of scope.
                        return
                elif self._format_style == "new":
                    keyword_arguments, implicit_pos_args, explicit_pos_args = utils.parse_format_method_string(
                        format_string
                    )

                    keyword_args_cnt = len(
                        set(k for k, l in keyword_arguments if not isinstance(k, int))
                    )
                    required_num_args = (
                        keyword_args_cnt + implicit_pos_args + explicit_pos_args
                    )
            except utils.UnsupportedFormatCharacter as ex:
                char = format_string[ex.index]
                self.add_message(
                    "logging-unsupported-format",
                    node=node,
                    args=(char, ord(char), ex.index),
                )
                return
            except utils.IncompleteFormatString:
                self.add_message("logging-format-truncated", node=node)
                return
        if num_args > required_num_args:
            self.add_message("logging-too-many-args", node=node)
        elif num_args < required_num_args:
            self.add_message("logging-too-few-args", node=node)
Checks that format string tokens match the supplied arguments.

        Args:
          node (astroid.node_classes.NodeNG): AST node to be checked.
          format_arg (int): Index of the format string in the node arguments.