What is the difference between deepcopy and shallow copy in Python?

What is the difference between deepcopy and shallow copy in Python?

In Python, a shallow copy creates a new object but inserts references into it to the objects found in the original. A deepcopy, on the other hand, creates a new object and recursively adds copies of nested objects found in the original.

Can you give me an example of each?

Sure! For a shallow copy, you can use copy.copy(). For a deepcopy, use copy.deepcopy(). Here's a quick example:

import copy

original = [1, 2, [3, 4]]
shallow = copy.copy(original)
deep = copy.deepcopy(original)

original[2][0] = 'Changed'

print(shallow)  # Output: [1, 2, ['Changed', 4]]
print(deep)     # Output: [1, 2, [3, 4]]

Why would I use one over the other?

Use a shallow copy when you want to copy an object but still want to share references to nested objects. Use a deepcopy when you need a completely independent copy of the object and its nested objects.

Are there performance implications between the two?

Yes, deepcopy can be slower and consume more memory because it recursively copies all objects. Shallow copy is faster since it only copies the outer object.