[FIXED] Base class variable does not store value which is set by Derived class

Issue

I am new to python. Base class/python file(Base.py).

SESSION_ID = ""

def m1():
    print "SESSION_ID in base: ",SESSION_ID

Derived class(Derived.py)

from Base import *

class Derived():
    def m2(self):
        global SESSION_ID
        SESSION_ID = 10
        print "SESSION_ID in derived: ", SESSION_ID

def main():
    c2 = Derived()
    c2.m2()
    m1()


if __name__ == "__main__":
    main()

When I execute Derived.py file below is the output:

SESSION_ID in derived:  10
SESSION_ID in base:  

I want the value which is set in m2() to be reflected in m1(). So the expected output is:

SESSION_ID in derived:  10
SESSION_ID in base:  10

Can you please help?

Solution

The global variable in a module is merely an attribute (i.e. a member entity) of that module.

As result of that when you use import *, the new local module global SESSION_ID is created, so the SESSION_ID in the base is immune to the changes you are doing in the Derived.

Basically, modifying base.SESSION_ID don't require usage of the global statement in the Derived.py, adjusting import is enough, see code below:

from settings import base


class Derived():
    def m2(self):
        base.SESSION_ID = 10
        print "SESSION_ID in derived: ", base.SESSION_ID

def main():
    c2 = Derived()
    c2.m2()
    base.m1()


if __name__ == "__main__":
    main()

Answered By - Andriy Ivaneyko