Aliases vs Clones: Why L2 = L1 Is Not a Copy

If `L1_copy = L1` copies nothing, why does mutating one name change the other — and what does that mean inside a function?

Finger exercises

Short drills on what this video just taught. Write the code, run the checks, and reveal the answer only if you are stuck.

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Exercise 1 of 5

One List, Three Names?

You're given nums = [10, 20, 30, 40]. Build a genuine clone of it and assign that to clone, then build an alias of it and assign that to alias.

(Vocabulary: is tests whether two names point at one and the same object. The slice that duplicates an entire list is a pair of square brackets with a single colon inside.)

# Build a clone and an alias of the list below.
nums = [10, 20, 30, 40]

clone = ...  # your code here
alias = ...  # your code here

# Build a clone and an alias of the list below.
nums = [10, 20, 30, 40]

clone = ...  # your code here
alias = ...  # your code here

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`clone` and `alias` are both lists

all three names see the same values

`clone` is a second object, not a second name

`alias` is a second name for the very same object

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