Method level

loguru/_logger.py:1535–1636

r"""Add, update or retrieve a logging level. Logging levels are defined by their ``name`` to which a severity ``no``, an ansi ``color`` tag and an ``icon`` are associated and possibly modified at run-time. To |log| to a custom level, you should necessarily use its name, the

(self, name, no=None, color=None, icon=None)

        return Logger(self._core, *options, [*patchers, patcher], extra)

    def level(self, name, no=None, color=None, icon=None):
        r"""Add, update or retrieve a logging level.

        Logging levels are defined by their ``name`` to which a severity ``no``, an ansi ``color``
        tag and an ``icon`` are associated and possibly modified at run-time. To |log| to a custom
        level, you should necessarily use its name, the severity number is not linked back to levels
        name (this implies that several levels can share the same severity).

        To add a new level, its ``name`` and its ``no`` are required. A ``color`` and an ``icon``
        can also be specified or will be empty by default.

        To update an existing level, pass its ``name`` with the parameters to be changed. It is not
        possible to modify the ``no`` of a level once it has been added.

        To retrieve level information, the ``name`` solely suffices.

        Parameters
        ----------
        name : |str|
            The name of the logging level.
        no : |int|
            The severity of the level to be added or updated.
        color : |str|
            The color markup of the level to be added or updated.
        icon : |str|
            The icon of the level to be added or updated.

        Returns
        -------
        ``Level``
            A |namedtuple| containing information about the level.

        Raises
        ------
        ValueError
            If attempting to access a level with a ``name`` that is not registered, or if trying to
            change the severity ``no`` of an existing level.

        Examples
        --------
        >>> level = logger.level("ERROR")
        >>> print(level)
        Level(name='ERROR', no=40, color='<red><bold>', icon='❌')
        >>> logger.add(sys.stderr, format="{level.no} {level.icon} {message}")
        1
        >>> logger.level("CUSTOM", no=15, color="<blue>", icon="@")
        Level(name='CUSTOM', no=15, color='<blue>', icon='@')
        >>> logger.log("CUSTOM", "Logging...")
        15 @ Logging...
        >>> logger.level("WARNING", icon=r"/!\\")
        Level(name='WARNING', no=30, color='<yellow><bold>', icon='/!\\\\')
        >>> logger.warning("Updated!")
        30 /!\\ Updated!
        """
        if not isinstance(name, str):
            raise TypeError(
                "Invalid level name, it should be a string, not: '%s'" % type(name).__name__
            )