6. Lists & Tuples

Understanding Vectors

A List in Python is a Dynamic Array. It stores pointers to objects. This means it has O(1) access time but can be slow to insert items in the middle.

Slicing

The power of colon :.

python
# [start:stop:step]
nums = [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]

print(nums[::2])   # [0, 2, 4, 6, 8] (Evens)
print(nums[::-1])  # [9, 8, ... 0]   (Reverse)

Tuples

Tuples are Immutable Lists. Why use them?

1. Safety: Data cannot be changed by accident.
2. Speed: Python optimizes memory for tuples.
3. Hashable: Can be used as dictionary keys (Lists cannot).

python
point = (10, 20)
x, y = point # Unpacking