Immutable vs Mutable types

Question

I\'m confused on what an immutable type is. I know the float object is considered to be immutable, with this type of example from my book:

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Answer 1

The simplest answer:

A mutable variable is one whose value may change in place, whereas in an immutable variable change of value will not happen in place. Modifying an immutable variable will rebuild the same variable.

Example:

>>>x = 5

Will create a value 5 referenced by x

x -> 5

>>>y = x

This statement will make y refer to 5 of x

x -------------> 5 <-----------y

>>>x = x + y

As x being an integer (immutable type) has been rebuild.

In the statement, the expression on RHS will result into value 10 and when this is assigned to LHS (x), x will rebuild to 10. So now

x--------->10

y--------->5