Trie

def graph(arr, layer=0, letters=1, word=0, graphized=[]):

    if layer==0:
        graph(arr, layer=1, graphized=graphized)
        return graphized

    elif letters<=len(arr[word]) and word<len(arr):
        cur_word=word

        while cur_word<len(arr) and arr[word][:letters-1] == arr[cur_word][:letters-1]:
            new_index=cur_word

            cur_let=arr[cur_word][letters-1]
            if cur_let not in graphized:
                graphized.append(cur_let)

            if letters < len(arr[cur_word]):
                if arr[cur_word-1][:letters]==arr[cur_word][:letters] and cur_word>0:
                    graphized.append([''])
                else:
                    graphized.append([])
                part=graphized[-1]
                new_index=graph(arr, layer+1, letters+1, cur_word, part)

            if new_index==cur_word:
                cur_word+=1
            else: cur_word=new_index

        return cur_word

    return word

#~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

def search(graph, word, letter=0):
    wlen=len(word)
    if letter<wlen and word[letter] in graph:
        list_ind=graph.index(word[letter])+1
        if len(graph)>list_ind:
            part=graph[list_ind]
            if isinstance(part, list):
                return search(part,word,letter+1)
            elif letter==wlen-1:
                return True
            else:
                return False
        elif letter==wlen-1:
            return True
        else:
            return False
    elif '' in graph and letter==wlen:
        return True
    else:
        return False