gistfile1.py

## Prelude.

from functools import partial
from itertools import chain, ifilter, islice, izip_longest

def compose(*funcs):
    """Return a function such that compose(a,b,c)(arg1, arg2, arg3)
       is equivalent to a(b(c(arg1, arg2, arg3)))."""
    # See http://bugs.python.org/issue1660179
    def _composefunc(*args, **kw):
        l = reversed(funcs)
        rv = l.next()(*args, **kw)
        for f in l:
            rv = f(rv)
        return rv
    return _composefunc

def concat(xs):
    return (y for x in xs for y in x)

concat_map = compose(concat, map)

def take(n, iterable):
    return islice(iterable, n)

def drop(n, iterable):
    return islice(iterable, n, None)

def splitat(n, xs):
    return (take(n, xs), drop(n, xs))

def prepend(xs):
    return partial(chain, xs)

def chunk(chunk_size, xs):
    def _grouper(n, xs, fillvalue=None):
        return izip_longest(*[iter(xs)]*n, fillvalue=fillvalue)
    fillvalue = object()
    xss = _grouper(chunk_size, xs, fillvalue)
    return (ifilter(lambda x: x is not fillvalue, xs) for xs in xss)


## Solution.

def wrap_line(width, prefix, line):
    head, tail = splitat(width, line)
    return [head] + map(prepend(prefix), chunk(width - len(prefix), tail))

def wrap_lines(width, prefix, lines):
    return concat_map(partial(wrap_line, width, prefix), lines)


## Hack.

normalize = ''.join


## Problem.

resp_lines = [
	str(range(i)) for i in range(20, 50,3)
]

width = 80
prefix = "   "

print '\n'.join(map(normalize, wrap_lines(width, prefix, resp_lines)))