Putting a matrix from a text file into a list
Not sure if it's possible to make this faster. But it can be better:

with open(path_to_file, 'rt') as fh:
    return [[int(value) for value in line.split()] for line in fh]


First of all, you should always use a with ... context manager when working with files. That way you cannot forget to close the file handle after you are done reading from it.

Other improvements:


More natural variable names
Simpler and more compact writing style using a list comprehension


Also keep in mind PEP8, the Python style guide.