CSC 110 Lab Week 11

Going around in a point in a grid

In this lab session we are going to focus on modularity.

Name your file look_around.py

You first will implement a function to make a grid (2D list) of all ‘o’ (single lower letter o character) of width (number of elements in each sublist) and height dimentions (number of rows).

# make_grid(width, height)
my_grid = make_grid(9, 9)
assert my_grid == [['o', 'o', 'o', 'o', 'o', 'o', 'o', 'o', 'o'],
                   ['o', 'o', 'o', 'o', 'o', 'o', 'o', 'o', 'o'],
                   ['o', 'o', 'o', 'o', 'o', 'o', 'o', 'o', 'o'],
                   ['o', 'o', 'o', 'o', 'o', 'o', 'o', 'o', 'o'],
                   ['o', 'o', 'o', 'o', 'o', 'o', 'o', 'o', 'o'],
                   ['o', 'o', 'o', 'o', 'o', 'o', 'o', 'o', 'o'],
                   ['o', 'o', 'o', 'o', 'o', 'o', 'o', 'o', 'o'],
                   ['o', 'o', 'o', 'o', 'o', 'o', 'o', 'o', 'o'],
                   ['o', 'o', 'o', 'o', 'o', 'o', 'o', 'o', 'o']]

To make sure you can see the result of modifications on your grid, write a print_grid function to print each row of the grid:

my_grid = make_grid(9, 9)
print_grid(my_grid)

['o', 'o', 'o', 'o', 'o', 'o', 'o', 'o', 'o']
['o', 'o', 'o', 'o', 'o', 'o', 'o', 'o', 'o']
['o', 'o', 'o', 'o', 'o', 'o', 'o', 'o', 'o']
['o', 'o', 'o', 'o', 'o', 'o', 'o', 'o', 'o']
['o', 'o', 'o', 'o', 'o', 'o', 'o', 'o', 'o']
['o', 'o', 'o', 'o', 'o', 'o', 'o', 'o', 'o']
['o', 'o', 'o', 'o', 'o', 'o', 'o', 'o', 'o']
['o', 'o', 'o', 'o', 'o', 'o', 'o', 'o', 'o']
['o', 'o', 'o', 'o', 'o', 'o', 'o', 'o', 'o']

Here’s the main part of the problem: given a grid (2D list of single characters), and given coordinates x and y, mutate the grid so that the coordinate and the positions around the coordinate hold the character 'x'.

Call your function mark_around because the idea is that you are marking the grid at (x, y) and around this position as well. The parameters for mark_around are the grid, x (row), and y (position inside row).

my_grid = make_grid(9, 9)
# mark_around(grid, x, y)
mark_around(my_grid, 4, 4)
print_grid(my_grid)

['o', 'o', 'o', 'o', 'o', 'o', 'o', 'o', 'o']
['o', 'o', 'o', 'o', 'o', 'o', 'o', 'o', 'o']
['o', 'o', 'o', 'o', 'o', 'o', 'o', 'o', 'o']
['o', 'o', 'o', 'x', 'x', 'x', 'o', 'o', 'o']
['o', 'o', 'o', 'x', 'x', 'x', 'o', 'o', 'o']
['o', 'o', 'o', 'x', 'x', 'x', 'o', 'o', 'o']
['o', 'o', 'o', 'o', 'o', 'o', 'o', 'o', 'o']
['o', 'o', 'o', 'o', 'o', 'o', 'o', 'o', 'o']
['o', 'o', 'o', 'o', 'o', 'o', 'o', 'o', 'o']

You should write not only the mark_around function, but another function that will be called inside mark_around. This function should be called within_limits and should return False and x or y are outside the limits of the grid. The parameters for within_limits are the grid, x (row), and y (position inside row).

my_grid = make_grid(4, 6)
assert within_limits(my_grid, -1, 0) == False
assert within_limits(my_grid, 0, 0) == True
assert within_limits(my_grid, 1, 2) == True
assert within_limits(my_grid, 5, 5) == False
assert within_limits(my_grid, 4, 6) == False
assert within_limits(my_grid, 5, 3) == True
assert within_limits(my_grid, 6, 4) == False

Development strategy

Once you have your within_limits function written, you can create nested loops for mark_around with the outer loop starting at x-1 and stopping at x+1. The inner loop should start at y-1 and stop at y+1. As long as the [i][j] subsetting of your grid is within limits of the grid, assign 'x' to that position.

Test cases

my_grid = make_grid(6, 9)
mark_around(my_grid, 3, 2)
print_grid(my_grid)

['o', 'o', 'o', 'o', 'o', 'o']
['o', 'o', 'o', 'o', 'o', 'o']
['o', 'x', 'x', 'x', 'o', 'o']
['o', 'x', 'x', 'x', 'o', 'o']
['o', 'x', 'x', 'x', 'o', 'o']
['o', 'o', 'o', 'o', 'o', 'o']
['o', 'o', 'o', 'o', 'o', 'o']
['o', 'o', 'o', 'o', 'o', 'o']
['o', 'o', 'o', 'o', 'o', 'o']

my_grid = make_grid(4, 6)
mark_around(my_grid, 0, 0)
print_grid(my_grid)

['x', 'x', 'o', 'o']
['x', 'x', 'o', 'o']
['o', 'o', 'o', 'o']
['o', 'o', 'o', 'o']
['o', 'o', 'o', 'o']
['o', 'o', 'o', 'o']

my_grid = make_grid(4, 6)
mark_around(my_grid, 5, 3)
print_grid(my_grid)

['o', 'o', 'o', 'o']
['o', 'o', 'o', 'o']
['o', 'o', 'o', 'o']
['o', 'o', 'o', 'o']
['o', 'o', 'x', 'x']
['o', 'o', 'x', 'x']