Python Copy objects (deep copy deepcopy and shallow copy copy)

When assigning values between objects in Python is passed by reference, the copy module in the standard library is required if the object needs to be copied.

1. Copy.copy a shallow copy copies only the parent object and does not copy the inner sub-objects of the object.

2. copy.deepcopy deep copy copy objects and their sub-objects
A good example:

Import Copy
A = [1, 2, 3, 4, [' A ', ' B ']] #原始对象

b = A #赋值, a reference to a passing object
c = Copy.copy (a) #对象拷贝, shallow copy
D = copy.deepcopy (a) #对象拷贝, deep copy

A.append (5) #修改对象a
A[4].append (' C ') #修改对象a中的 [' A ', ' B '] Array object

print ' A = ', a
print ' B = ', b
print ' c = ', C
print ' d = ', D

Output Result:
A = [1, 2, 3, 4, [' A ', ' B ', ' C '], 5]
b = [1, 2, 3, 4, [' A ', ' B ', ' C '], 5]
c = [1, 2, 3, 4, [' A ', ' B ', ' C ']]
D = [1, 2, 3, 4, [' A ', ' B ']]

Python Copy objects (deep copy deepcopy and shallow copy copy)