def test_copy_class():
from xoutil import Unset
from xoutil.eight import _py3
from xoutil.eight.meta import metaclass
from xoutil.objects import copy_class
u = str if _py3 else unicode
class MetaFoo(type):
pass
class Foo(metaclass(MetaFoo)):
a = 1
b = 2
c = 3
d = 4
class Baz(Foo):
e = 5
index = {k: getattr(Foo, k) for k in 'abcd'}
Bar = copy_class(Foo)
assert Bar.a == Foo.a and Bar.b and Bar.c and Bar.d
Egg = copy_class(Foo, ignores=['b', 'c'])
assert getattr(Egg, 'b', Unset) is Unset
Egg = copy_class(Foo, ignores=[lambda k: index.get(k) and index.get(k) > 2])
assert Egg.a == Foo.a
assert getattr(Egg, 'c', Unset) is Unset
Named = copy_class(Foo, new_name='Named')
assert Named.__name__ == 'Named'
Named = copy_class(Foo, new_name=u('Named'))
assert Named.__name__ == 'Named'
import fnmatch
pattern = lambda attr: fnmatch.fnmatch(attr, 'a*')
Egg = copy_class(Foo, ignores=[pattern])
assert getattr(Egg, 'a', Unset) is Unset
import re
_pattern = re.compile('^a')
pattern = lambda attr: _pattern.match(attr)
Egg = copy_class(Foo, ignores=[pattern])
assert getattr(Egg, 'a', Unset) is Unset
def thesefy(target):
'''Allow an object to participate in queries.
Example as a wrapper::
class People(object):
# ...
pass
query = (who for who in thesefy(People))
Example as a decorator::
@thesefy
class People(object):
pass
query = (who for who in People)
If your classes already support the iterable protocol (i.e implement
``__iter__``) this does nothing.
'''
if getattr(target, '__iter__', None):
return target
class new_meta(type(target)):
def __iter__(self):
return (x for x in this if isinstance(x, self))
def next(self):
raise StopIteration
__next__ = next
from xoutil.objects import copy_class
new_class = copy_class(target, meta=new_meta)
return new_class
def thesefy(target, make_subquery=True):
'''Allow an object to participate in queries.
Example as a wrapper::
class People:
# ...
pass
query = (who for who in thesefy(People))
Example as a decorator::
@thesefy
class People:
pass
query = (who for who in People)
If `target` already support the iterable protocol (i.e implement
``__iter__``), return it unchanged.
If `make_subquery` is True, then the query shown above will be equivalent
to::
query = (who for who in (x for x in this if isinstance(x, People)))
If `make_subquery` is False, `thesefy` injects an ``__iter__()`` that
simply returns the same object and a ``next()`` method that immediately
stops the iteration.
Notice that in order to use `make_subquery` you call `thesefy`:func: as a
decorator-returning function::
class Person:
pass
query = (x for x in thesefy(make_subquery=False)(Person))
# or simply as a decorator
@thesefy(make_subquery=False)
class Person:
pass
'''
if getattr(target, '__iter__', None):
return target
class new_meta(type(target)):
if make_subquery:
def __iter__(self):
return (x for x in this if isinstance(x, self))
else:
def __iter__(self):
return self
def next(self):
raise StopIteration
__next__ = next
from xoutil.objects import copy_class
new_class = copy_class(target, meta=new_meta)
return new_class