Reference replication, shard Copy, full replication in Python

Reference replication, shard Copy, full replication in Python

First look directly at the example:

>>>l1=[1,2,3]>>>L11 = L1>>>l2=[4,5, L1]>>>l2[4,5, [1,2,3]]>>>L3 = l2[:]>>>l3[4,5, [1,2,3]]>>>ImportCopy>>>L4 = copy.deepcopy (L2)>>>l4[4,5, [1,2,3]]>>>l2[1] =6>>>l2[4,6, [1,2,3]]>>>l3[4,5, [1,2,3]]>>>l4[4,5, [1,2,3]]>>>l1[0] =7>>>l1[7,2,3]>>>l11[7,2,3]>>>l2[4,6, [7,2,3]]>>>l3[4,5, [7,2,3]]>>>l4[4,5, [1,2,3]]

Description

1. Copying using the Shared object application will only add a new reference to the existing object and will not generate new objects in memory (see L11 vs. L1).
2. Using a Shard method to copy a sequence type such as a list, only the contents of the current sequence are copied, and the data structures within the sequence are not copied (see L1, L2, L3 contrast).
3. Dictionaries can also be copied with copy methods, but with 2 limitations.
4. The Copy standard Template Library is able to generate a complete copy, eliminating the problem of not copying the data structures in the sequence in the previous article (see Comparison of L3 and L4 values).
5. 2 and 3 are called top-level replication and cannot replicate nested data structures.

Reference replication, shard Copy, full replication in Python