#TIL : Reference assign object variable

When you have a object x and assign y = x, y will be a ref of x (it looks like pointer of C). So changing property of y means changing property of x.

Ex :

x = {"a": 1, "b": 2}
y = x
y['a'] = 100
print x['a'] # Result is 100

So if you want clone the value, use copy lib :

import copy
x = {"a": 1, "b": 2}
y = copy.deepcopy(x)
y['a'] = 100
print x['a'] # Result is 1