Hi Diez,
first, thanks for your comprehensive answer.
Diez B. Roggisch wrote:
> Hans-Peter Jansen schrieb:
>>
>> I'm trying to generate a bunch of similar classes, where some are
>> contained in list attributes of others, e.g.:
>
> All your code below shows that you don't create classes, but _instances_
> of classes. So - is that what you mean to do?
Yes, exactly. Sorry for the confusion..
>
> In a nutshell, you do this:
>
> b = B()
> res = []
> for i in xrange(3):
> b.id = i
> res.append(b)
>
> Always the same b.
>
> What you seem to want is this
>
> >>> class B(object):
> ... pass
> ...
> >>> res = []
> >>> for i in xrange(3):
> ... class BSubClass(B):
> ... pass
> ... BSubClass.id = i
> ... res.append(BSubClass)
> ...
> >>> print [c.id for c in res]
> [0, 1, 2]
>
> I'm still not sure what you want - do you want instances created, or
> classes? For the former, you need constructor calls on your classes, and
> pass the class instead of an instance. Like this:
>
>
> class B(object):
> pass
>
>
> def g(cls):
> for i in xrange(3):
> o = cls()
> o.id = i
> yield o
>
> list(g(B))
Yes, that did the trick. Silly me. Rookie error. Here's what I was after:
#!/usr/bin/env python
# -*- coding: utf8 -*-
class A(object):
"A"
def __init__(self):
self.id = None
self.b = []
class B(object):
"B"
def __init__(self):
self.id = None
class Gen(object):
"Gen"
def records(self, cls):
for n in range(3):
i = cls()
i.id = "%s%s" % (i.__doc__, n)
yield i
class GenA(Gen):
def __init__(self):
self.genB = GenB()
def records(self):
for a in Gen.records(self, A):
for b in self.genB.records():
a.b.append(b)
yield a
class GenB(Gen):
def records(self):
return Gen.records(self, B)
aRecs = []
bRecs = []
for i, r in enumerate(GenB().records()):
bRecs.append(r)
print i, r.id, r
for i, r in enumerate(GenA().records()):
aRecs.append(r)
print i, r.id, r
for b in r.b:
print b.id, b
created pretty nice different _instances_ of what I wanted:
0 B0 <__main__.B object at 0xb7cacfec>
1 B1 <__main__.B object at 0xb7cae04c>
2 B2 <__main__.B object at 0xb7cae08c>
0 A0 <__main__.A object at 0xb7cae12c>
B0 <__main__.B object at 0xb7cae1ac>
B1 <__main__.B object at 0xb7cae1ec>
B2 <__main__.B object at 0xb7cae22c>
1 A1 <__main__.A object at 0xb7cae16c>
B0 <__main__.B object at 0xb7cae2ac>
B1 <__main__.B object at 0xb7cae2ec>
B2 <__main__.B object at 0xb7cae32c>
2 A2 <__main__.A object at 0xb7cae26c>
B0 <__main__.B object at 0xb7cae3ac>
B1 <__main__.B object at 0xb7cae3ec>
B2 <__main__.B object at 0xb7cae42c>
Didn't found the forest because all the trees. Thanks again.
Greetings to Berlin,
Pete
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