Permutations

2022-01-10.py

question = """
Given a string s, you can transform every letter individually to be lowercase or 
uppercase. Return a list of all possible permutations you could create from s.

Example:

$ capPermutations("ab2")
$ ["ab2","aB2","Ab2","AB2"]

$ capPermutations("35p")
$ ["35p","35P"]

"""

import re

char_p = re.compile(r'[a-zA-Z]')

def capPermutations(string):
    perm_array = []
    for ch in string:
        new_perm_array = []
        char_m = char_p.search(ch)
        char_a = []
        if char_m:
            char_a.append(ch.upper())
            char_a.append(ch.lower())
        else:
            char_a.append(ch)
        if len(perm_array):
            for perm in perm_array:
                for char in char_a:
                    new_perm_array.append(perm + char)
        else:
            for char in char_a:
                new_perm_array.append(char)
        perm_array = new_perm_array
    return perm_array

print(capPermutations("ab2"))
print(capPermutations("35p"))