Why are the elements connected?

Question

Python

Childish question for pythonists.
When creating a two-dimensional list like this:

matrix = [[0] * 10] *10;
matrix[1][1] = 100;
print matrix;

I get the value 100 in each nested list.
Does this method work by reference?
Thank you.

Answer 1

Yes, you could even say, in a sense, that everything in Python is passed by reference. But data types are divided into mutable and immutable. Lists are mutable, but numbers are not.
Arrays can be specified using a special syntax - list comprehensions:
matrix = [[0]*10 for x in range(10)]