[Answer]-How to avoid variable to be persistent across many requests?

The following is the correct class definition you want.

class SomeClass:
    def __init__(self,value):
        self.some_variable = value

    def setVariable(self,value):
        self.some_variable = value

    def getVariable(self):
        return self.some_variable

This will set the attribute on the instance rather than on the class object.

>>> a = SomeClass(5)
>>> a.some_variable # Just as expected
5
>>> b = SomeClass(10)
>>> b.some_variable # This is its own variable
10
>>> b.some_variable = 20 # This won't change 'a'
>>> a.some_variable # Hasn't changed
5

I might also want to note that getters and setters are often not want you want when writing python since you can do instance.some_variable = 5 without the need of a getter or setter.