A pythonic way to insert a space before capital letters

Question

I\'ve got a file whose format I\'m altering via a python script. I have several camel cased strings in this file where I just want to insert a single space before the capital l

Answer 1

I think regexes are the way to go here, but just to give a pure python version without (hopefully) any of the problems ΤΖΩΤΖΙΟΥ has pointed out:

def splitCaps(s):
    result = []
    for ch, next in window(s+" ", 2):
        result.append(ch)
        if next.isupper() and not ch.isspace():
            result.append(' ')
    return ''.join(result)

window() is a utility function I use to operate on a sliding window of items, defined as:

import collections, itertools

def window(it, winsize, step=1):
    it=iter(it)  # Ensure we have an iterator
    l=collections.deque(itertools.islice(it, winsize))
    while 1:  # Continue till StopIteration gets raised.
        yield tuple(l)
        for i in range(step):
            l.append(it.next())
            l.popleft()