Python copy object (deep copy deepcopy and light copy)

Objects in Python are assigned values by reference. to copy objects, use the copy module in the standard library. 1. copy. copy: only the parent object is copied, and the internal sub-objects of the object are not copied.
2. copy. deepcopy: deep copy object and its sub-objects
A good example:
Import Copy
A = [ 1 , 2 , 3 , 4 ,[ ' A ' , ' B ' ] # Original object

B = A # Assign values to pass object references
C = Copy. copy () # Object copy and shortest copy
D = Copy. deepcopy () # Object copy, deep copy

A. append ( 5 ) # Modify object
A [ 4 ]. Append ( ' C ' ) # Modify the ['A', 'B'] array object in object

Print ' 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']