Python direct assignment, shallow copy, and deep copy parsing

• Direct Assignment: is actually the object's reference (alias).

• shallow copy (copy): copies the parent object and does not copy the inner sub-object of the object.

• deep Copy (deepcopy): The Deepcopy method of the Copy module, which completely copies the parent object and its child objects.

Example of a shallow copy of a dictionary>>>A= {1:[1,2,3]} >>>B=A.Copy()>>>A,B ({1:[1,2,3]}, {1:[1,2,3]})>>>A[1].Append(4)>>>ab ({1: [1234 ]}, {1: [12 34]})

Deep copy requires the introduction of the Copy module:

Instance>>>Import Copy>>>C=Copy.Deepcopy(A)>>>A,C ({1:[1,2,3,4]}, {1:[1,2,3,4]})>>>A[1].Append(5)>>>A,c ({1: [1 23 45]}, {1: [1234 ]}) /span> Analytical

1,B = A: assignment references, both A and B point to the same object.

2, B = a.copy (): shallow Copy, A and B are separate objects, but their child objects still point to a uniform object (which is a reference).

B = Copy.deepcopy (a): deep Copy, A and B completely copy the parent object and its child objects, both are completely independent.

Python direct assignment, shallow copy, and deep copy parsing