Python list slice syntax used for no obvious reason

Question

I occasionally see the list slice syntax used in Python code like this:

newList = oldList[:]

Surely this is just the same as:

Answer 1

Shallow Copy: (copies chunks of memory from one location to another)

a = ['one','two','three']

b = a[:]

b[1] = 2

print id(a), a #Output: 1077248300 ['one', 'two', 'three']
print id(b), b #Output: 1077248908 ['one', 2, 'three']

Deep Copy: (Copies object reference)

a = ['one','two','three']

b = a

b[1] = 2


print id(a), a #Output: 1077248300 ['one', 2, 'three']
print id(b), b #Output: 1077248300 ['one', 2, 'three']