PYTHON

2d list in python

ar = [[0 for j in range(m)] for i in range(n)]

2d list in python

def list_2D(r, c):
    l = []
    for i in range(r):
        x = [0] * c
        l.append(x)
    return l

accessing 2d list in python

Two-dimensional lists can be accessed similar 
to their one-dimensional counterpart. Instead of providing 
a single pair of brackets [ ] we will use an additional set for 
each dimension past the first.

#The below code demonstrates

heights = [["Noelle", 61], ["Ali", 70], ["Sam", 67]]

#To access "Noelle" or her age, would type the following 

noelles_height = heights[0][1] 
print(noelles_height)

#This would print out:
61

Here are the index numbers to access data for the list heights:

Element	            Index
"Noelle"    	heights[0][0]
61	            heights[0][1]
"Ali"	        heights[1][0]
70	            heights[1][1]
"Sam"	        heights[2][0]
67	            heights[2][1]