From c527fd1f14c27855a37f2e8ac5346ce8d940ced2 Mon Sep 17 00:00:00 2001 From: Tudor Florea Date: Thu, 16 Oct 2014 03:05:19 +0200 Subject: initial commit for Enea Linux 4.0-140929 Migrated from the internal git server on the daisy-enea-point-release branch Signed-off-by: Tudor Florea --- bitbake/lib/bb/namedtuple_with_abc.py | 255 ++++++++++++++++++++++++++++++++++ 1 file changed, 255 insertions(+) create mode 100644 bitbake/lib/bb/namedtuple_with_abc.py (limited to 'bitbake/lib/bb/namedtuple_with_abc.py') diff --git a/bitbake/lib/bb/namedtuple_with_abc.py b/bitbake/lib/bb/namedtuple_with_abc.py new file mode 100644 index 0000000000..f5e0a3f3d5 --- /dev/null +++ b/bitbake/lib/bb/namedtuple_with_abc.py @@ -0,0 +1,255 @@ +# http://code.activestate.com/recipes/577629-namedtupleabc-abstract-base-class-mix-in-for-named/ +#!/usr/bin/env python +# Copyright (c) 2011 Jan Kaliszewski (zuo). Available under the MIT License. + +""" +namedtuple_with_abc.py: +* named tuple mix-in + ABC (abstract base class) recipe, +* works under Python 2.6, 2.7 as well as 3.x. + +Import this module to patch collections.namedtuple() factory function +-- enriching it with the 'abc' attribute (an abstract base class + mix-in +for named tuples) and decorating it with a wrapper that registers each +newly created named tuple as a subclass of namedtuple.abc. + +How to import: + import collections, namedtuple_with_abc +or: + import namedtuple_with_abc + from collections import namedtuple + # ^ in this variant you must import namedtuple function + # *after* importing namedtuple_with_abc module +or simply: + from namedtuple_with_abc import namedtuple + +Simple usage example: + class Credentials(namedtuple.abc): + _fields = 'username password' + def __str__(self): + return ('{0.__class__.__name__}' + '(username={0.username}, password=...)'.format(self)) + print(Credentials("alice", "Alice's password")) + +For more advanced examples -- see below the "if __name__ == '__main__':". +""" + +import collections +from abc import ABCMeta, abstractproperty +from functools import wraps +from sys import version_info + +__all__ = ('namedtuple',) +_namedtuple = collections.namedtuple + + +class _NamedTupleABCMeta(ABCMeta): + '''The metaclass for the abstract base class + mix-in for named tuples.''' + def __new__(mcls, name, bases, namespace): + fields = namespace.get('_fields') + for base in bases: + if fields is not None: + break + fields = getattr(base, '_fields', None) + if not isinstance(fields, abstractproperty): + basetuple = _namedtuple(name, fields) + bases = (basetuple,) + bases + namespace.pop('_fields', None) + namespace.setdefault('__doc__', basetuple.__doc__) + namespace.setdefault('__slots__', ()) + return ABCMeta.__new__(mcls, name, bases, namespace) + + +exec( + # Python 2.x metaclass declaration syntax + """class _NamedTupleABC(object): + '''The abstract base class + mix-in for named tuples.''' + __metaclass__ = _NamedTupleABCMeta + _fields = abstractproperty()""" if version_info[0] < 3 else + # Python 3.x metaclass declaration syntax + """class _NamedTupleABC(metaclass=_NamedTupleABCMeta): + '''The abstract base class + mix-in for named tuples.''' + _fields = abstractproperty()""" +) + + +_namedtuple.abc = _NamedTupleABC +#_NamedTupleABC.register(type(version_info)) # (and similar, in the future...) + +@wraps(_namedtuple) +def namedtuple(*args, **kwargs): + '''Named tuple factory with namedtuple.abc subclass registration.''' + cls = _namedtuple(*args, **kwargs) + _NamedTupleABC.register(cls) + return cls + +collections.namedtuple = namedtuple + + + + +if __name__ == '__main__': + + '''Examples and explanations''' + + # Simple usage + + class MyRecord(namedtuple.abc): + _fields = 'x y z' # such form will be transformed into ('x', 'y', 'z') + def _my_custom_method(self): + return list(self._asdict().items()) + # (the '_fields' attribute belongs to the named tuple public API anyway) + + rec = MyRecord(1, 2, 3) + print(rec) + print(rec._my_custom_method()) + print(rec._replace(y=222)) + print(rec._replace(y=222)._my_custom_method()) + + # Custom abstract classes... + + class MyAbstractRecord(namedtuple.abc): + def _my_custom_method(self): + return list(self._asdict().items()) + + try: + MyAbstractRecord() # (abstract classes cannot be instantiated) + except TypeError as exc: + print(exc) + + class AnotherAbstractRecord(MyAbstractRecord): + def __str__(self): + return '<<<{0}>>>'.format(super(AnotherAbstractRecord, + self).__str__()) + + # ...and their non-abstract subclasses + + class MyRecord2(MyAbstractRecord): + _fields = 'a, b' + + class MyRecord3(AnotherAbstractRecord): + _fields = 'p', 'q', 'r' + + rec2 = MyRecord2('foo', 'bar') + print(rec2) + print(rec2._my_custom_method()) + print(rec2._replace(b=222)) + print(rec2._replace(b=222)._my_custom_method()) + + rec3 = MyRecord3('foo', 'bar', 'baz') + print(rec3) + print(rec3._my_custom_method()) + print(rec3._replace(q=222)) + print(rec3._replace(q=222)._my_custom_method()) + + # You can also subclass non-abstract ones... + + class MyRecord33(MyRecord3): + def __str__(self): + return '< {0!r}, ..., {0!r} >'.format(self.p, self.r) + + rec33 = MyRecord33('foo', 'bar', 'baz') + print(rec33) + print(rec33._my_custom_method()) + print(rec33._replace(q=222)) + print(rec33._replace(q=222)._my_custom_method()) + + # ...and even override the magic '_fields' attribute again + + class MyRecord345(MyRecord3): + _fields = 'e f g h i j k' + + rec345 = MyRecord345(1, 2, 3, 4, 3, 2, 1) + print(rec345) + print(rec345._my_custom_method()) + print(rec345._replace(f=222)) + print(rec345._replace(f=222)._my_custom_method()) + + # Mixing-in some other classes is also possible: + + class MyMixIn(object): + def method(self): + return "MyMixIn.method() called" + def _my_custom_method(self): + return "MyMixIn._my_custom_method() called" + def count(self, item): + return "MyMixIn.count({0}) called".format(item) + def _asdict(self): # (cannot override a namedtuple method, see below) + return "MyMixIn._asdict() called" + + class MyRecord4(MyRecord33, MyMixIn): # mix-in on the right + _fields = 'j k l x' + + class MyRecord5(MyMixIn, MyRecord33): # mix-in on the left + _fields = 'j k l x y' + + rec4 = MyRecord4(1, 2, 3, 2) + print(rec4) + print(rec4.method()) + print(rec4._my_custom_method()) # MyRecord33's + print(rec4.count(2)) # tuple's + print(rec4._replace(k=222)) + print(rec4._replace(k=222).method()) + print(rec4._replace(k=222)._my_custom_method()) # MyRecord33's + print(rec4._replace(k=222).count(8)) # tuple's + + rec5 = MyRecord5(1, 2, 3, 2, 1) + print(rec5) + print(rec5.method()) + print(rec5._my_custom_method()) # MyMixIn's + print(rec5.count(2)) # MyMixIn's + print(rec5._replace(k=222)) + print(rec5._replace(k=222).method()) + print(rec5._replace(k=222)._my_custom_method()) # MyMixIn's + print(rec5._replace(k=222).count(2)) # MyMixIn's + + # None that behavior: the standard namedtuple methods cannot be + # overriden by a foreign mix-in -- even if the mix-in is declared + # as the leftmost base class (but, obviously, you can override them + # in the defined class or its subclasses): + + print(rec4._asdict()) # (returns a dict, not "MyMixIn._asdict() called") + print(rec5._asdict()) # (returns a dict, not "MyMixIn._asdict() called") + + class MyRecord6(MyRecord33): + _fields = 'j k l x y z' + def _asdict(self): + return "MyRecord6._asdict() called" + rec6 = MyRecord6(1, 2, 3, 1, 2, 3) + print(rec6._asdict()) # (this returns "MyRecord6._asdict() called") + + # All that record classes are real subclasses of namedtuple.abc: + + assert issubclass(MyRecord, namedtuple.abc) + assert issubclass(MyAbstractRecord, namedtuple.abc) + assert issubclass(AnotherAbstractRecord, namedtuple.abc) + assert issubclass(MyRecord2, namedtuple.abc) + assert issubclass(MyRecord3, namedtuple.abc) + assert issubclass(MyRecord33, namedtuple.abc) + assert issubclass(MyRecord345, namedtuple.abc) + assert issubclass(MyRecord4, namedtuple.abc) + assert issubclass(MyRecord5, namedtuple.abc) + assert issubclass(MyRecord6, namedtuple.abc) + + # ...but abstract ones are not subclasses of tuple + # (and this is what you probably want): + + assert not issubclass(MyAbstractRecord, tuple) + assert not issubclass(AnotherAbstractRecord, tuple) + + assert issubclass(MyRecord, tuple) + assert issubclass(MyRecord2, tuple) + assert issubclass(MyRecord3, tuple) + assert issubclass(MyRecord33, tuple) + assert issubclass(MyRecord345, tuple) + assert issubclass(MyRecord4, tuple) + assert issubclass(MyRecord5, tuple) + assert issubclass(MyRecord6, tuple) + + # Named tuple classes created with namedtuple() factory function + # (in the "traditional" way) are registered as "virtual" subclasses + # of namedtuple.abc: + + MyTuple = namedtuple('MyTuple', 'a b c') + mt = MyTuple(1, 2, 3) + assert issubclass(MyTuple, namedtuple.abc) + assert isinstance(mt, namedtuple.abc) -- cgit v1.2.3-54-g00ecf