python list copy

If we need to copy a list, we can use a special method, which I will tell you today.

I first define a list

a=[1,2,34]

Then I check the address of the object through the built-in method id()

print id(a)

Object address: 11488352

Then I Copy a list of a and copy it to the variable b

b = a[:]

I output the variable b

print b

The result is [1, 2, 34], which is the same as a, and then I Look at the address in List B below.

print id(b)

Object address: 11511448

It can be seen that the addresses of the two objects are different, indicating that a new list object is generated by re-copying, not the assignment of a reference.