What's the difference between list1 = [] list2 = [] and list1 = list2 = [] in python?

Question

I just started using python and I am trying to initialize two lists using list comprehensions. Like this

list1 = list2 = [0.0] * 57

When i do this and insert these lists with values i am getting a different set of values (incorrect values) when compared to the values i get when i initialize these lists seperately. Like

list1 = [0.0] * 57
list2 = [0.0] * 57

What is happening in the first case ? Why am I getting different answers for these 2 cases ?

Answer 1

The first one sets list1 and list2 to both refer to the same list. The second one defines a new list for each name.