Sort a list of strings based on regular expression match

Question

I have a text file that looks a bit like:

random text random text, can be anything blabla %A blabla
random text random text, can be anything blabla %D blabla         


        

Answer 1

what about this? hope this helps.

def k(line):
    v = line.partition("%")[2]
    v = v[0] if v else 'z' # here z stands for the max value
    return v
print ''.join(sorted(open('data.txt', 'rb'), key = k))