# 1209.py

a=[1,5,0,2]; b=a; b.sort(); print a
# [0, 1, 2, 5]

b[2]=17; print a
# [0, 1, 17, 5]

b=a[:].sort(); print a
# [0, 1, 17, 5]
# a non e' cambiata.

b=a[:].reverse(); print a
# [0, 1, 17, 5]
# a non e' cambiata.

def azzeraprimo (a): a[0]=0

a=[5,6]; b=a; azzeraprimo(b)
print a # [0, 6]

#######################################

a=[[1,2],[3,4]]
b=a[:] # oppure b=list(a)
b[1][0]=17; print a
# [[1, 2], [17, 4]]

#######################################

import copy

a=[[1,2],[3,4]]
b=copy.deepcopy(a)
b[1][0]=17; print a
# [[1, 2], [3, 4]]
# a non e' cambiata.

#######################################

a=[1.5,0,2]; b=a
print b is a # True

a=[[1,2],[3,4]]; b=a[:]
print b is a
# False
print b[0] is a[0]
# True

a=[[1,2],[3,4]]
b=copy.deepcopy(a)
print b is a
# False
print b[0] is a[0] # False
print b==a # True