Mutability Cheat Sheet


Mutability, simply put: the contents of a mutable object can be changed, while the contents of an immutable object cannot be.

Simple Types

All of the simple data types we covered first are immutable

type use mutable?
int, float, decimal store numbers no
str store strings no
bool store True or False no

Container Types

For the mutability of the container types we covered in this chapter, check this helpful list:

container type use mutable?
list ordered group of items, accessible by position yes
set mutable unordered group consisting only of immutable items. useful for set operations (membership, intersection, difference, etc) yes
tuple contain ordered groups of items in an immutable collection no
dict contains key value pairs yes