Find all list permutations of splitting a string in Python

Question

I have a string of letters that I\'d like to split into all possible combinations (the order of letters must be remain fixed), so that:

s = \'monkey\'
         


        

Answer 1

My solution allows you to also set a threshold for the minimum size of sub string

This is my code:

def split_string (s, min_str_length = 2, root_string=[], results=[] ):
    """
    :param s: word to split, string
    :param min_str_length: the minimum character for a sub string
    :param root_string:  leave empty
    :param results: leave empty
    :return: nested list of all possible combinations of word split according to the minimum substring length
    """
    for i in range(min_str_length,len(s)):
        if i == min_str_length:
            primary_root_string=root_string
        else:
            root_string = primary_root_string
        if len(s[i:])>= min_str_length :
            results.append(list(chain(*[root_string,[s[:i]],[s[i:]]])))
            root_string = list(chain(*[root_string,[s[:i]]]))
            split_string(s[i:], min_str_length, root_string, results)
    return results

Examples of use:

Input: split_string ('monkey', min_str_length = 1, root_string=[], results=[] )
Output: 
[['m', 'onkey'],
 ['m', 'o', 'nkey'],
 ['m', 'o', 'n', 'key'],
 ['m', 'o', 'n', 'k', 'ey'],
 ['m', 'o', 'n', 'k', 'e', 'y'],
 ['m', 'o', 'n', 'ke', 'y'],
 ['m', 'o', 'nk', 'ey'],
 ['m', 'o', 'nk', 'e', 'y'],
 ['m', 'o', 'nke', 'y'],
 ['m', 'on', 'key'],
 ['m', 'on', 'k', 'ey'],
 ['m', 'on', 'k', 'e', 'y'],
 ['m', 'on', 'ke', 'y'],
 ['m', 'onk', 'ey'],
 ['m', 'onk', 'e', 'y'],
 ['m', 'onke', 'y'],
 ['mo', 'nkey'],
 ['mo', 'n', 'key'],
 ['mo', 'n', 'k', 'ey'],
 ['mo', 'n', 'k', 'e', 'y'],
 ['mo', 'n', 'ke', 'y'],
 ['mo', 'nk', 'ey'],
 ['mo', 'nk', 'e', 'y'],
 ['mo', 'nke', 'y'],
 ['mon', 'key'],
 ['mon', 'k', 'ey'],
 ['mon', 'k', 'e', 'y'],
 ['mon', 'ke', 'y'],
 ['monk', 'ey'],
 ['monk', 'e', 'y'],
 ['monke', 'y']]

or

Input: split_string ('monkey', min_str_length = 2, root_string=[], results=[] )
Output: [['mo', 'nkey'], ['mo', 'nk', 'ey'], ['mon', 'key'], ['monk', 'ey']]