Split a single column into two

Question

The data format I have is as follows:

###John###
someData1
someData2
SomeData3
###Mike###
someData1
someData2
###Ford###
someData1
someData2
SomeData3
someData4
someData5
SomeData6

I want the output to be:

John  someData1
      someData2
      someData3

Mike  someData1
      someData2

Ford  someData1
      someData2
      someData3
      someData4
      someData5
      someData6

The problem here is the number of data (somedata?) beneath each name differs and is not pre known. The only piece I've to work with is the leading ### characters that signifies the beginning of a new name.

Somedata? is a single word. Any idea on how to accomplish this?

Answer 1

I'd use something like:

def fixup(iterable):
    it = iter(iterable)
    for x in it:
        if x.startswith('###'):
            yield '\n{0}\t{1}'.format(x.strip('#'),next(it))
        else:
            yield '\t{0}'.format(x)

This'll give you an extra newline on the first line, but that can easily be stripped off if you really want to.

Answer 2

An itertools approach:

from itertools import groupby

with open('yourfile') as fin:
    for k, g in groupby(fin, lambda L: L.startswith('###')):
        if k:
            name = next(g).strip('#\n')
        else:
            print '{}\t{}'.format(name, next(g)),
            for line in g:
                print '\t{}'.format(line),
            print