in scancode/lib/util.py [0:0]
def register_pattern(name, pattern_factory, override=None):
"""
Registers the specified pattern factory.
*name* (:class:`str`) is the name to register the pattern factory
under.
*pattern_factory* (:class:`~collections.abc.Callable`) is used to
compile patterns. It must accept an uncompiled pattern (:class:`str`)
and return the compiled pattern (:class:`.Pattern`).
*override* (:class:`bool` or :data:`None`) optionally is whether to
allow overriding an already registered pattern under the same name
(:data:`True`), instead of raising an :exc:`AlreadyRegisteredError`
(:data:`False`). Default is :data:`None` for :data:`False`.
"""
if not isinstance(name, string_types):
raise TypeError("name:{!r} is not a string.".format(name))
if not callable(pattern_factory):
raise TypeError("pattern_factory:{!r} is not callable.".format(pattern_factory))
if name in _registered_patterns and not override:
raise AlreadyRegisteredError(name, _registered_patterns[name])
_registered_patterns[name] = pattern_factory