Compress text to Unicode text for Discord Custom IDs.

alt-test.py

# alternative to convert number strings to printable ascii, for smaller deta base strings, ' ' space reserved
ascii_chars = list(r'''!"#$%&'()*+,-./0123456789:;<=>?@ABCDEFGHIJKLMNOPQRSTUVWXYZ[\]^_`abcdefghijklmnopqrstuvwxyz{|}~''')

def power_sum(values, base, offset = 0):
    return sum(value * base ** (index + offset) for index, value in enumerate(values))

def convert_text(text, chars):
    base = len(chars) + 1
    chars =  {char : index + 1 for index, char in enumerate(chars)}
    temp = []
    result = ''
    for char in text:
        value = chars[char] # indexerror = missing that char in char set
        if value * base ** len(temp) + power_sum(temp, base, 1) > len(ascii_chars): 
            result += ascii_chars[power_sum(temp, base)]
            temp = [value]
        else:
            temp.append(value)
    result += ascii_chars[power_sum(temp, base)]
    return result
    
def revert_text(text, chars):
    base = len(chars) + 1
    chars = list(chars)
    result = ''
    for char in text:
        value = ascii_chars.index(char)
        while value:
            result += chars[(value % base) - 1]
            value //= base
    return result
  
text = '10123456789012345679999999999999' 

chars = ''.join(set(text))
print('Base:', len(chars), '\n')

print('Start text ({}): {}'.format(len(text), text), '\n')

text = convert_text(text, chars)
print('Ascii text ({}): {}'.format(len(text), text), '\n')

text = revert_text(text, chars)
print('Revert text ({}): {}'.format(len(text), text), '\n')

output.txt

Base: 11

Start text (500): 1012345678901234567:1012345678901234567:1012345678901234567:1012345678901234567:1012345678901234567:1012345678901234567:1012345678901234567:1012345678901234567:1012345678901234567:1012345678901234567:1012345678901234567:1012345678901234567:1012345678901234567:1012345678901234567:1012345678901234567:1012345678901234567:1012345678901234567:1012345678901234567:1012345678901234567:1012345678901234567:1012345678901234567:1012345678901234567:1012345678901234567:1012345678901234567:1012345678901234567:

Unicode text (100): 𩠘𑗑𩠚𹷑𩠘𑗑𩠚𹷑𩠘𑗑𩠚𹷑𩠘𑗑𩠚𹷑𩠘𑗑𩠚𹷑𩠘𑗑𩠚𹷑𩠘𑗑𩠚𹷑𩠘𑗑𩠚𹷑𩠘𑗑𩠚𹷑𩠘𑗑𩠚𹷑𩠘𑗑𩠚𹷑𩠘𑗑𩠚𹷑𩠘𑗑𩠚𹷑𩠘𑗑𩠚𹷑𩠘𑗑𩠚𹷑𩠘𑗑𩠚𹷑𩠘𑗑𩠚𹷑𩠘𑗑𩠚𹷑𩠘𑗑𩠚𹷑𩠘𑗑𩠚𹷑𩠘𑗑𩠚𹷑𩠘𑗑𩠚𹷑𩠘𑗑𩠚𹷑𩠘𑗑𩠚𹷑𩠘𑗑𩠚𹷑

Revert text (500): 1012345678901234567:1012345678901234567:1012345678901234567:1012345678901234567:1012345678901234567:1012345678901234567:1012345678901234567:1012345678901234567:1012345678901234567:1012345678901234567:1012345678901234567:1012345678901234567:1012345678901234567:1012345678901234567:1012345678901234567:1012345678901234567:1012345678901234567:1012345678901234567:1012345678901234567:1012345678901234567:1012345678901234567:1012345678901234567:1012345678901234567:1012345678901234567:1012345678901234567:

test.py

MAX_UNICODE = 1_114_111 # 0x10FFFF is max unicode code point
START_SURROGATE = 55_296 # 0xD800 to 0xDFFF are surrogates, unprintable/pointers
MAX_SURROGATE = 2_048 # 0x800

def validate_unicode(value, reverse = False):
    if value >= START_SURROGATE:
        value -= MAX_SURROGATE * (2 * int(reverse) - 1) # 1 when true, -1 when false
    return value

def power_sum(values, base, offset = 0):
    return sum(value * base ** (index + offset) for index, value in enumerate(values))

def convert_text(text, chars):
    base = len(chars) + 1
    chars =  {char : index + 1 for index, char in enumerate(chars)}
    temp = []
    result = ''
    for char in text:
        value = chars[char] # indexerror = missing that char in char set
        if value * base ** len(temp) + power_sum(temp, base, 1) > MAX_UNICODE:
            result += chr(validate_unicode(power_sum(temp, base)))
            temp = [value]
        else:
            temp.append(value)
    result += chr(validate_unicode(power_sum(temp, base)))
    return result
    
def revert_text(text, chars):
    base = len(chars) + 1
    chars = list(chars)
    result = ''
    for char in text:
        value = validate_unicode(ord(char), True)
        while value:
            result += chars[(value % base) - 1]
            value //= base
    return result
  
text = '1012345678901234567:' * 25 # storing 25 user ids in a custom id

chars = ''.join(set(text))
print('Base:', len(chars), '\n')

print('Start text ({}): {}'.format(len(text), text), '\n')

text = convert_text(text, chars)
print('Unicode text ({}): {}'.format(len(text), text), '\n')

text = revert_text(text, chars)
print('Revert text ({}): {}'.format(len(text), text), '\n')