#
# ps6pr5.py (Problem Set 6, Problem 5)
#
# 2-D Lists
#
# Computer Science 111
# 

import random

def create_grid(num_rows, num_cols):
    """ creates and returns a 2-D list of 0s with the specified dimensions.
        inputs: num_rows and num_cols are non-negative integers
    """
    grid = []
    
    for r in range(num_rows):
        row = [0] * num_cols     # a row containing width 0s
        grid += [row]

    return grid

def print_grid(grid):
    """ prints the 2-D list specified by grid in 2-D form,
        with each row on its own line.
        input: grid is a 2-D list
    """
    num_rows = len(grid)
    for r in range(num_rows):
        if r == 0:
            print('[', end='')
        else:
            print(' ', end='')
        if r < num_rows - 1:
            print(str(grid[r]) + ',')
        else:
            print(str(grid[r]) + ']')

def random_grid(num_rows, num_cols):
    """ creates and returns a 2-D list with the specified dimensions
        in which each cell is assigned a random integer from 0-9.
        inputs: num_rows and num_cols are non-negative integers
    """
    grid = create_grid(num_rows, num_cols)

    for r in range(num_rows):
        for c in range(num_cols):
            grid[r][c] = random.choice(range(10))
            
    return grid