Depth copy, assignment and reference in Python

Simply put, if object A is stored in a mutable object such as a list or dictionary, a shallow copy of B to A is just a copy of the first layer of the object, and modifying the second layer of B still affects two objects.

A deep copy does not affect the original object.

Import

Copy.copy () Shallow copy

Copy.deepcopy () deep copy

The assignment operation is more like a reference, the new assignment creates a new memory address, points to the change, and the original memory address exists.

Reference article Address:

Python Basics (5): In-depth understanding of assignments, references, copies, scopes in Python

http://my.oschina.net/leejun2005/blog/145911

Depth copy, assignment and reference in Python