From 3905e7e64059b45479894ba1fdfb0ef9cef64475 Mon Sep 17 00:00:00 2001 From: James Taylor Date: Sat, 16 Feb 2019 23:41:52 -0800 Subject: basic subscriptions system --- python/attr/filters.py | 52 ++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 52 insertions(+) create mode 100644 python/attr/filters.py (limited to 'python/attr/filters.py') diff --git a/python/attr/filters.py b/python/attr/filters.py new file mode 100644 index 0000000..f1c69b8 --- /dev/null +++ b/python/attr/filters.py @@ -0,0 +1,52 @@ +""" +Commonly useful filters for :func:`attr.asdict`. +""" + +from __future__ import absolute_import, division, print_function + +from ._compat import isclass +from ._make import Attribute + + +def _split_what(what): + """ + Returns a tuple of `frozenset`s of classes and attributes. + """ + return ( + frozenset(cls for cls in what if isclass(cls)), + frozenset(cls for cls in what if isinstance(cls, Attribute)), + ) + + +def include(*what): + """ + Whitelist *what*. + + :param what: What to whitelist. + :type what: :class:`list` of :class:`type` or :class:`attr.Attribute`\\ s + + :rtype: :class:`callable` + """ + cls, attrs = _split_what(what) + + def include_(attribute, value): + return value.__class__ in cls or attribute in attrs + + return include_ + + +def exclude(*what): + """ + Blacklist *what*. + + :param what: What to blacklist. + :type what: :class:`list` of classes or :class:`attr.Attribute`\\ s. + + :rtype: :class:`callable` + """ + cls, attrs = _split_what(what) + + def exclude_(attribute, value): + return value.__class__ not in cls and attribute not in attrs + + return exclude_ -- cgit v1.2.3