Extracting matrix from a text file

[telekab1@hotmail.com]

Hello to all!!

I am new in python, and I am running it on Mac with Smultron editor. I
need to read a textfile that includes numbers (in a matrix form),
indexes, and strings, like this:

Marsyas-kea distance matrix for MIREX 2007 Audio Similarity Exchange
Q/R        1                   2                   3
4                5
1        0                  4.54592        4.36685
5.29463        3.85728
2        4.54592        0                  3.97667
5.02151        4.64284
3        4.36685        3.97667        0
4.98743        4.83683
4        5.29463        5.02151        4.98743
0                  6.04393
5        3.85728        4.64284        4.83683        6.04393        0

My code to get this information is:

matrix = open("dmatrix_5.txt");

while 1:
    mat = matrix.readline()
    if not mat:
    	break
    pass # do something
    print mat



So I just want to keep the matrix in the "middle" for math
computations.

        0                  4.54592        4.36685
5.29463        3.85728
        4.54592        0                  3.97667
5.02151        4.64284
        4.36685        3.97667        0
4.98743        4.83683
        5.29463        5.02151        4.98743
0                  6.04393
        3.85728        4.64284        4.83683        6.04393        0


I've seen and tried a lot of ways, like split or isinstance.. but
never get the wanted result.... does anyone have an idea, or hint?
Thank you once more for your help!

Best Regards,
Bea