How to copy a python class?
In general, inheritance is the right way to go, as the other posters have already pointed out.
However, if you really want to recreate the same type with a different name and without inheritance then you can do it like this:
class B(object):
x = 3
CopyOfB = type('CopyOfB', B.__bases__, dict(B.__dict__))
b = B()
cob = CopyOfB()
print b.x # Prints '3'
print cob.x # Prints '3'
b.x = 2
cob.x = 4
print b.x # Prints '2'
print cob.x # Prints '4'
You have to be careful with mutable attribute values:
class C(object):
x = []
CopyOfC = type('CopyOfC', C.__bases__, dict(C.__dict__))
c = C()
coc = CopyOfC()
c.x.append(1)
coc.x.append(2)
print c.x # Prints '[1, 2]' (!)
print coc.x # Prints '[1, 2]' (!)
The right way to "copy" a class, is, as you surmise, inheritance:
class B(A):
pass
You could use a factory function:
def get_A():
class A(object):
ARG = 1
return A
A = get_A()
B = get_A()