Metaclasses are not called in subclasses. What did I wrong?
Létező
letezo at fw.hu
Sat Oct 28 19:35:29 EDT 2006
I use Python 2.4.4. Please read the code below:
-----------------------------------------------------------
from new import classobj
def mymeta(name,bases,clsdict):
print 'meta: %s'%name
return classobj(name,bases,clsdict)
class A(object):
__metaclass__=mymeta
class B(A):
pass
-----------------------------------------------------------
This should print
meta: A
meta: B
when classes A and B are created. But only meta: B is missing,
since mymeta() is not called when class B is created.
Related python documentation states that mymeta() must be called when B is
created, since metaclasses are looked up in bases classes if not found in
the dictionary of the class itself.
>From Python 2.4.4's manual: "Otherwise, if there is at least one base class,
its metaclass is used (this looks for a __class__ attribute first and if not
found, uses its type)."
Thanks for your help.
Viktor
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