I have this code:
class A(object):
def __init__(self):
print " A"
class B(A):
def __init__(self):
print "B"
x=B()
print "Done"
the result is: "B" gets printed why does it not print "A", eventhough class B inheritance A
-
2Because you're overriding the init method?Green Lithium– Green Lithium2016-08-11 00:07:12 +00:00Commented Aug 11, 2016 at 0:07
-
Python doesn't automatically call the superclass constructor for you; you need to explicitly call it yourself. The fact that this just passes silently is one of the design flaws of Python's class system implementation.user2357112– user23571122016-08-11 00:11:56 +00:00Commented Aug 11, 2016 at 0:11
Add a comment
|
1 Answer
If you want to use A's __init__ while also using B's __init__, then try:
class A(object):
def __init__(self):
print " A"
class B(A):
def __init__(self):
A.__init__(self)
print "B"
x=B()
print "Done"
Or, if you would prefer not to mention the superclass by name:
class A(object):
def __init__(self):
print " A"
class B(A):
def __init__(self):
super(B, self).__init__()
print "B"
x=B()
print "Done"
Both of these produce the output:
A
B
Done
1 Comment
user2357112
Never use
super(self.__class__, self). It fails as soon as you make a descendant of B and self.__class__ isn't B any more.