Set defaulr parser instance

    Parameters
    ----------
    parser : instance or string
        An instance or registered name of parser class.
        The specified parser instance will be used when user did not specified
        :attr:`parser` in :func:`maidenhair.functions.load` function.

    See also
    --------
    :func:`maidenhair.utils.plugins.Registry.register` : Register new class

def set_default_parser(parser):
    """
    Set defaulr parser instance

    Parameters
    ----------
    parser : instance or string
        An instance or registered name of parser class.
        The specified parser instance will be used when user did not specified
        :attr:`parser` in :func:`maidenhair.functions.load` function.

    See also
    --------
    :func:`maidenhair.utils.plugins.Registry.register` : Register new class

    """
    if isinstance(parser, basestring):
        parser = registry.find(parser)()
    if not isinstance(parser, BaseParser):
        parser = parser()
    global _parser
    _parser = parser