Module 5: Lists in Python
List Properties
Lists have three important properties: they keep order, you can change them, and they allow duplicate values.
About 8 minutes
1. Ordered
Items stay in the order you put them. The first item is always first unless you move it.
2. Mutable (changeable)
You can add, remove, or change items after creating the list — unlike tuples later.
3. Allow duplicates
Example code
scores = [90, 85, 90, 92] print(scores) # 90 appears twice — that is OK
List [ ]
Ordered, changeable
Tuple ( )
Ordered, fixed — later
In data science, lists of numbers often become NumPy arrays later — faster for big math.
Practice
Make a list with duplicate numbers. Print it to see duplicates are allowed.
Key takeaways
- Lists are ordered — position matters.
- Lists are mutable — you can change them.
- Duplicate values are allowed.
Quick check: List Properties
Question 1 of 2
Mutable means: