Variables are pointers in Python
Python's variables are not buckets that contain objects; they're pointers. Assignment statements don't copy: they point a variable to a value (and multiple variables can "point" to the same value).
Article at https://pym.dev/variables-are-pointers/
More #Python screencasts at https://pym.dev/screencasts/
00:00 Changing two lists at once
01:09 Variables are separate from objects
01:38 Assignment statements don't copy
02:04 Explicitly copying a list
02:30 Variables are like pointers, not buckets