The normalize function doesn't return 'm' for 'rn', 'r' followed by 'n'

[lazydog2]

When using the normalize function for 'rn', 'r' followed by 'n', it doesn't include 'm' in the returned list despite the fact that applying confusable_characters to 'm' includes 'rn' in the list, presumably normalize is only applying to single characters e.g:

>>> normalize('rn')
['rn']  # should return ['m', 'rn']
>>> confusable_characters('m')
['𝑚', 'μ', 'ᗰ', 'Ḿ', '𝘔', 'Ⲙ', '𝓂', 'ℳ', '𝑴', '𝓜', 'м', '𝚳', '𝚖', '𝙼', '𝜧', 'Ꮇ', '𝑀', '𝘮', '𝕞', '𝓶', '𑜀', 'ｍ', '𝗺', '𝞛', '𝗆', 'ᛖ', '𝛭', 'Ⅿ', 'M', 'rn', 'µ', '𝙢', 'ṃ', '𝐦', 'ꭑ', 'Ṃ', '𝕸', 'ⲙ', '𝒎', 'ḿ', 'ϻ', 'ꓟ', 'Ｍ', 'm', 'ꮇ', 'ⅿ', '𐊰', '𝔐', 'Ϻ', 'Μ', '𝝡', 'Ṁ', '𝖬', '𝐌', '𐌑', '𝔪', '𝙈', '𝕄', 'ṁ', '𑣣', 'М', '𝖒', '𝗠']

[lazydog2]

This version of normalize seems to handle multi-character confusables and closely matches the behavior of the existing normalize function:

import string
from copy import copy

def normalize(string, prioritize_chars=False, prioritized_char_set=string.ascii_lowercase):
    cache = {}
    for (k, v) in {key:set([value2.lower() for value2 in value if all(is_ascii(char) and char not in NON_NORMAL_ASCII_CHARS and (not prioritize_chars or char in prioritized_char_set) for char in value2) and (len(key) == 1 or key != value2)]) for (key,value) in CONFUSABLE_MAP.items() if string.lower().startswith(key.lower()) and (len(key) == 1 or key != value)}.items():
        cache[k.lower()].extend(v) if k.lower() in cache else cache.update({k.lower():list(v)})
    for x in range(1, len(string)):
        completed_string = string[0:x]
        remaining_string = string[x:]
        matching_confusables = {}
        for (k, v) in {key:set([value2.lower() for value2 in value if all(is_ascii(char) and char not in NON_NORMAL_ASCII_CHARS and (not prioritize_chars or char in prioritized_char_set) for char in value2) and (len(key) == 1 or key != value2)]) for (key,value) in CONFUSABLE_MAP.items() if remaining_string.lower().startswith(key.lower())}.items():
            matching_confusables[k.lower()].update(v) if k.lower() in matching_confusables else matching_confusables.update({k.lower():set(v)})
        for (k, v) in matching_confusables.items():
            normal_forms = [product(cache[completed_string], v)]
            cache_key = f'{completed_string}{k}'
            cache[cache_key].extend(normal_forms) if cache_key in cache else cache.update({cache_key:normal_forms})
        del cache[completed_string]
    
    for temp in next_string(cache[string]):
        yield temp

def next_string(node):
    if isinstance(node, tuple) and isinstance(node[0], str):
        yield f'{node[0]}{node[1]}'
    elif isinstance(node, tuple) and isinstance(node[0], product):
        for temp in next_string(copy(node[0])):
            yield f'{temp}{node[1]}'
    else:
        for temp in node:
            if isinstance(temp, tuple) and isinstance(temp[0], str):
                yield f'{temp[0]}{temp[1]}'
            elif isinstance(temp, tuple) and isinstance(temp[0], product):
                for temp2 in next_string(copy(temp[0])):
                    yield f'{temp2}{temp[1]}'
            else:
                for temp2 in copy(temp):
                    if isinstance(temp2, tuple) and isinstance(temp2[0], str):
                        yield f'{temp2[0]}{temp2[1]}'
                    else:
                        for temp3 in next_string(copy(temp2)):
                            yield f'{temp3}'

[drothlis]

To clarify, is_confusable('rn', 'm') does work as expected (it returns True). It's only normalize that doesn't.