2D Matrix in Python

Question

I have a requirement where the input is of form

3 3

ABB

BAA

AAA

The first line of input indicates Number of row(3) and columns(3) respectively. And below lines indicate input string, which forms the 3*3 matrix.

I tried using Dictionary to create it and was able to achieve it, but is using Dictionary correct way or most efficient way. Is there any other way to create a 2D matrix of this form?

Using Lists:

print "Enter the value of row:"
r = input()
print "Enter the value of column:"
c = input()

m=[]
for i in xrange(r):
    m.append([])
    for j in xrange(c):
        m[i].append(raw_input())
print m

The Input and output: Enter the value of row: 2 Enter the value of column: 2 ABB AAA BBB CCC
[['ABB', 'AAA'], ['BBB', 'CCC']]

The Input and output: Enter the value of row: 2 Enter the value of column: 2 ABB AAA BBB CCC
[['ABB', 'AAA'], ['BBB', 'CCC']]

I needed it of the form:

[[A,B,B],[A,A,A],[B,B,B],[C,C,C]]

Answer 1

Following code creates a 2d list for the above data.

f = open("data.txt")
rows_count, cols_count = f.readline().split()
line_count = 0 
list2D = []
while line_count < int(rows_count):
    line = f.readline().strip().strip("\n")
    if len(line) == 0:
        # blank line
        continue
    row = list(line)[0:int(cols_count)]
    list2D.append(row)
    line_count += 1
print list2D

Output:

[['A', 'B', 'B'], ['B', 'A', 'A'], ['A', 'A', 'A']]