Python - Recursion and tree of a word

Question

I'm creating a little program that requires me to do the following: Starting from a word I need to make all possible words according to the following rule: starting with the word 'help', 'help' me become root of the tree, then every time I raise a point of the first type ('h') and then the word becomes me 'elp', then I take always the word 'help' but at this point I raise the second letter ('e') and then the word becomes me 'hlp', then I take always the initial word 'help' and lift up the third letter ('l'), and then the word becomes me 'hep', then I take always the initial word 'help', and I raise the fourth letter ('p'), and then the word becomes me 'hel' .

Then later, in the words found ('elp', 'hlp', 'hep', 'hel') I have to repeat the same thing until you get to the leaves. All of these words should be included in a list(also in the tree, obviously). Obviously there is a recursion, but my problem is this ... in the recursion are not any good! :(

Thank you if you can help me, it's really important.

PS: Or rather, as I understand it, I have to create all possible combinations without changing the order of letters

Answer 1

You need to code recursive function. This function should create new words and call itself with each new word as an argument. I would recommend you to read some documentation about strings in Python.

The sample function:

def getWords(word):

    result = {}

    for x in range(1, len(word)+1):
        newWord = word[0:x-1] + word[x:]
        result[newWord] = getWords(newWord)

    return result

Recursion is here: result[newWord] = getWords(newWord). We call our function for every new word.

You may improve it with some if/else statements. Now it returns dictionary even for one char word.

{   'elp': {   'el': {'e': {}, 'l': {}},
               'ep': {'e': {}, 'p': {}},
               'lp': {'l': {}, 'p': {}}}