code HELP

Implement feline_fixes, which is a diff function that returns the minimum number of edit operations needed to transform the start word into the goal word.

There are three kinds of edit operations:

Add a letter to start,
Remove a letter from start,
Substitute a letter in start for another.
Each edit operation contributes 1 to the difference between two words.

>>> big_limit = 10
>>> feline_fixes("cats", "scat", big_limit)       # cats -> scats -> scat
2
>>> feline_fixes("purng", "purring", big_limit)   # purng -> purrng -> purring
2
>>> feline_fixes("ckiteus", "kittens", big_limit) # ckiteus -> kiteus -> kitteus -> kittens
3
We have provided a template of an implementation in cats.py. This is a recursive function with three recursive calls. One of these recursive calls will be similar to the recursive call in sphinx_swap.

You may modify the template however you want or delete it entirely.

If the number of edits required is greater than limit, then feline_fixes should return any number larger than limit and should minimize the amount of computation needed to do so.

These two calls to feline_fixes should take about the same amount of time to evaluate:

>>> limit = 2
>>> feline_fixes("ckiteus", "kittens", limit) > limit
True
>>> sphinx_swap("ckiteusabcdefghijklm", "kittensnopqrstuvwxyz", limit) > limit
True










def feline_fixes(start, goal, limit):
    """A diff function that computes the edit distance from START to GOAL."""
    # gl = goal
    # st = start
    # word = ''
    # for i in st:
    #     for x in gl:
    #         if i == x:
    #             word += x
    #             gl.replace(x, '')
    #             break
    # return abs(len(goal) - len(word))
    #

    # BEGIN PROBLEM 7
    if limit < 0:
        return 2
    #basecase
    if start == goal: # Fill in the condition
        # BEGIN
        return 0
        # END
    if len(start) < 2 or len(goal) < 2:
            return 1

    if(start[0] == goal[0]):
        substitute_diff = feline_fixes(start[1:], goal[1:], limit - 1)
        add_diff = limit
        remove_diff = limit
    else:
        add_diff = 1 + feline_fixes(goal[0] + start, goal, limit - 1)
        remove_diff = 1 + feline_fixes(start[1:], goal, limit - 1)
        substitute_diff = 1 + feline_fixes(start[1:], goal[1:], limit - 1)
    # BEGIN
    return min(add_diff, remove_diff, substitute_diff)