Generates a compact word diff

Generate a compact word diff.py

import difflib

tags = {'+': ('<ins>', '</ins>'), '-': ('<del>', '</del>'), ' ': (' ', '')}

left = "An edit to create a new revision that the diffs thing. I am now adding some more text so that I can test the diffs."
right = "The beginning has now been changed. An edit to create a new revision that the diffs thing. And make some changes here and there. Let's add a totally new paragraph.\n\nOkay, enough. This is entirely new paragraph. We really need to build a cool diff thingy."

# Generates a compact word diff
prev_start, prev_end = None, ''
prev_item = ''
diff = []

differ = difflib.ndiff(left.split(), right.split())
for item in differ:
    tag = tags.get(item[0])
    
    if not tag: continue

    if prev_start == tag[0]:
        prev_item += item[1:]
    else:
        diff.append(prev_item + prev_end)
        prev_start, prev_end = tag
        prev_item = prev_start + item[1:]
diff.append(prev_item + prev_end)

return " ".join(diff)

Earlier I was using this. Yuck!

for item in differ:
    if item.startswith('+'):
        if prev_start == '<ins>':
            prev_item += item[1:]
        else:
            diff.append(prev_item + prev_end)
            prev_start, prev_end = '<ins>', '</ins>'
            prev_item = prev_start + item[1:]

    elif item.startswith('-'):
        if prev_start == '<del>':
            prev_item += item[1:]
        else:
            diff.append(prev_item + prev_end)
            prev_start, prev_end = '<del>', '</del>'
            prev_item = prev_start + item[1:]

    elif item.startswith(' '):
        if prev_start == ' ':
            prev_item += item[1:]
        else:
            diff.append(prev_item + prev_end)
            prev_start, prev_end = ' ', ''
            prev_item = item