Deep Copy & Shallow Copy

# 얕은복사 => 0-depth value copy
l = [[1,2,3],[4,5,6]]
ll = l[:]
assert id(l) != id(ll)
assert id(l[0]) == id(ll[0])

# 깊은복사 => N-depth recursive value copy
from copy import deepcopy
l = [[1,2,3],[4,5,6]]
ll = deepcopy(l)
assert id(l) != id(ll)
assert id(l[0]) != id(ll[0])