copy_deepcopy.py

# This code is for self study.
# Remider of the difference between copy.copy and copy.deepcopy

# immutable objects
print('immutable object')
a = 'abc'
b = a

print("a:{}, id(a):{}".format(a, id(a)))
print("b:{}, id(b):{}".format(b, id(b)))

print('resubstituting...')
a = 'abcd'

print("a:{}, id(a):{}".format(a, id(a)))
print("b:{}, id(b):{}".format(b, id(b)))

# mutable objects
print('mutable object')
a = list('a b c'.split(' '))
b = a

print("a:{}, id(a):{}".format(a, id(a)))
print("b:{}, id(b):{}".format(b, id(b)))

print('resubstituting...')
a.append('d')

print("a:{}, id(a):{}".format(a, id(a)))
print("b:{}, id(b):{}".format(b, id(b)))

import copy
print('check copy and deep copy')

a = [['a'], ['b']]
b = a
c = copy.copy(a)
d = copy.deepcopy(a)
e = a[:]

print("a:{}, id(a):{}".format(a, id(a)))
print("b:{}, id(b):{}".format(b, id(b)))
print("c:{}, id(c):{}".format(c, id(c)))
print("d:{}, id(d):{}".format(d, id(d)))
print("e:{}, id(e):{}".format(e, id(e)))

print('resubstituting...')
a[0].append('c')

print("a:{}, id(a):{}".format(a, id(a)))
print("b:{}, id(b):{}".format(b, id(b)))
print("c:{}, id(c):{}".format(c, id(c)))
print("d:{}, id(d):{}".format(d, id(d)))
print("e:{}, id(e):{}".format(e, id(e)))

print('resubstituting...')
a.append('d')

print("a:{}, id(a):{}".format(a, id(a)))
print("b:{}, id(b):{}".format(b, id(b)))
print("c:{}, id(c):{}".format(c, id(c)))
print("d:{}, id(d):{}".format(d, id(d)))
print("e:{}, id(e):{}".format(e, id(e)))