_init() not called automatically , when an object is made.

[Neeta Singh]

Pls refer to the given below program:

class t2:
    a=0
    def _init_(self):
        t2.a=10
    def f1(self,temp):
        self.a=temp
    def f2(self):
        print self.a
O1=t2()
O1.f2()
O1.f1(1000)
O1.f2()
O1.a=2000
O1.f2()

The result is :
0
1000
2000
And when called explicitly :

class t2:
    a=0
    def _init_(self):
        t2.a=10
    def f1(self,temp):
        self.a=temp
    def f2(self):
        print self.a
O1=t2()
O1._init_()
O1.f2()
O1.f1(1000)
O1.f2()
O1.a=2000
O1.f2()

gives us
10
1000
2000

[bvdet]

You have defined method "__init__" as "_init_". "__init__" (2 leading and trailing underscores) will be called when an instance is created, but not "_init_".

[dwblas]

Also you are using both class and instance attributes named "a", which are not the same.

class T2:
     a=0
     def __init__(self):
         T2.a=10
     def f1(self,temp):
         self.a=temp
     def f2(self):
         print self.a

class T3:
    def __init__(self):
        T2.a=20

O1=T2()
O1.f2()
O1.f1(1000)
O1.f2()
O1.a=2000
O1.f2()

print T2.a
third = T3()
print T2.a

[Neeta Singh]

Verified.
Thanks for the guidance.