Overriding __init__() questions

[grocery_stocker]

What's the difference between doing something calling A.__init__(self)
like in the following...

[cdalten@localhost ~]$ python
Python 2.4.3 (#1, Oct 1 2006, 18:00:19)
[GCC 4.1.1 20060928 (Red Hat 4.1.1-28)] on linux2
Type "help", "copyright", "credits" or "license" for more information..... def __init__(self):
.... pass
........ def __init__(self, x):
.... A.__init__(self)
.... self.x = x
.... print x
....Traceback (most recent call last):

versus something like the following....

[cdalten@localhost ~]$ python
Python 2.4.3 (#1, Oct 1 2006, 18:00:19)
[GCC 4.1.1 20060928 (Red Hat 4.1.1-28)] on linux2
Type "help", "copyright", "credits" or "license" for more information..... def __init__(self):
.... pass
........ def __init__(self, x):
.... self.x = x
.... print x
....Traceback (most recent call last):

Just curious because the former seems to be common when using the
python Thread module.

 

[Terry Reedy]

What's the difference between doing something calling A.__init__(self)
like in the following...

[cdalten@localhost ~]$ python
Python 2.4.3 (#1, Oct 1 2006, 18:00:19)
[GCC 4.1.1 20060928 (Red Hat 4.1.1-28)] on linux2
Type "help", "copyright", "credits" or "license" for more information.... def __init__(self):
... pass
...... def __init__(self, x):
... A.__init__(self)
... self.x = x
... print x
...Traceback (most recent call last):

versus something like the following....

[cdalten@localhost ~]$ python
Python 2.4.3 (#1, Oct 1 2006, 18:00:19)
[GCC 4.1.1 20060928 (Red Hat 4.1.1-28)] on linux2
Type "help", "copyright", "credits" or "license" for more information.... def __init__(self):
... pass
...... def __init__(self, x):
... self.x = x
... print x

In one you call A.__init__ and the other you don't. If A.__init__ does
something useful, as it usually would, then not calling it would not get
that useful work done. Or you repeat the useful code of A.__init__ in
B.__init__, which is not a good idea, especially when you have to change
that code in two places.