scanning 2d array in python
If you want to take n lines of input where each line contains m space separated integers like:
1 2 3
4 5 6 
7 8 9 
a=[] // declaration 
for i in range(0,n):   //where n is the no. of lines you want 
 a.append([int(j) for j in input().split()])  // for taking m space separated integers as input
