Need help and suggestions

[nilamo]

    if flag is 1:
        return True
    else:
        return False

Don't use is like that. It should only be used to check for object identity, such as something is None. flag is 1 will not work on all versions of python, and only works on cpython because small integers are cached instead of reused (ie: please don't rely on implementation details). More generally, if you CAN use ==, then you SHOULD use ==.

Also, that whole if statement at the end can just be replaced with return flag == 1. Or, more simply, as just return flag, since it'll only ever be 1 or 0.

Also, because flag only ever has two values, and those values imply on/off or yes/no or good/bad, it should be a bool with a value of either True or False, instead of 1/0.