On Tue, Aug 30, 2016 at 09:08:13PM +0000, monik...@netzero.net wrote: > OK so somebodys remark that there is a default __init__ provided was not > correct.
It is correct. The default __init__ is provided by object, the root of the class hierarchy. > What about old style classes? When we have a class that has no parent. > and it does not inherit from object since it is old class - and this > class has no __init__, does __new__ call __init__? For old-style classes, __new__ doesn't exist at all. The behaviour of creating a new instance is hard-coded into the interpreter, and __init__ is only called if it exists. You can define a method __new__, but it won't be called: # In Python 2 py> class NewStyle(object): ... def __new__(cls): ... print "called __new__" ... return super(NewStyle, cls).__new__(cls) ... def __init__(self): ... print "called __init__" ... py> instance = NewStyle() called __new__ called __init__ py> py> class OldStyle: ... def __new__(cls): ... print "called __new__" ... return super(OldStyle, cls).__new__(cls) ... def __init__(self): ... print "called __init__" ... py> instance = OldStyle() called __init__ In Python 3, old-style classes are gone. Even in Python 2, they're discouraged. -- Steve _______________________________________________ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: https://mail.python.org/mailman/listinfo/tutor
