Tutorial 17/20 — Advanced Logic
Python: 2D Lists
The Grid System. Lists within lists for complex mapping.
The Hook
Instead of a simple line of data, a 2D list is a GRID.
- Spreadsheets (Rows & Columns)
- Cinema Seats (Row A, Seat 5)
- Game Maps (X, Y Coordinates)
We access data using two sets of brackets: grid[row][col].
Matrix Synthesis
# Cinema Seating Plan (2D)
seats = [
["A1", "A2", "A3"], # Row 0
["B1", "B2", "B3"], # Row 1
["C1", "C2", "C3"] # Row 2
]
# Accessing Row 1, Seat 1 (Middle)
print(seats[1][1]) # Prints "B2"
Cognitive Visualisation:
[0,0]
[0,1]
[0,2]
[1,0]
[1,1]
[1,2]
[2,0]
[2,1]
[2,2]
"Row First, then Column"
Logic Gate
Predict Output
A 2D list matrix looks like this:
matrix = [
[15, 20],
[18, 22]
]
print(matrix[1][0])
[15, 20],
[18, 22]
]
print(matrix[1][0])
Level 46: Bronze
Grid Update
"The center spot "-" at Row 1, Column 1 needs to be updated. Change it to 'X'."
> matrix_write_standby
Level 47: Silver
Row Scanner
"A list contains multiple rows of data. Calculate the sum of the second row (Index 1)."
> scanner_module_active
Level 48: Gold
Matrix Loop
Coordinate Logic Engine
- Loop through each
rowin the matrix. - Inside that, loop through each item in the row.
- Print every item individually.
- TIP: This is a Nested Loop (Loop-inside-a-loop).
> nested_vector_online