The true meaning of mutable & Immutable in Python

• mutable → Changeable / modifiable

• immutable → Unchangeable / unmodifiable

• Python works in a way that only a few programming languages do.

    X = 10
    Y = X
    X = 20
    print(X) # 20
    print(Y) # 10
  

What happened here, right?

• Let’s go, step by step:

1. Python first stores the value 10 in a memory location. Its reference is then passed to the variable X.

2. Variable Y is created and refers to the value whose reference is stored in variable X i.e. 10.

3. Then, a new value ‘20’ is stored in the memory, and X refers to it.

4. Now, X is referring to ‘20’ and Y is still referring to ‘10’.

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I hope this helps.

Keep working on your ability to recall.