url_encoder.py

from baseconv import BaseConverter

# Project setup:
#   python3 -m venv .
#   . bin/activate
#   pip install python-baseconv
#   python3 git_url_encoder.py

BASE58_ALPHABET = '123456789abcdefghijkmnopqrstuvwxyzABCDEFGHJKLMNPQRSTUVWXYZ'
base58 = BaseConverter(BASE58_ALPHABET, sign='-')

# Reduced character set, order is the same as ASCII set, see https://ascii-code.com
ALPHABET = '0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ-'

# Custom encoder tutorial https://medium.com/swlh/creating-custom-character-encoding-to-save-space-5cc1e53b8f34
def my_encode(value):
    char_codes = [ALPHABET.index(char) for char in value.upper()]
    result = 0
    for index, char_code in enumerate(char_codes):
        result = result + char_code * pow(len(ALPHABET), len(char_codes) - 1 - index)
    return result

before_encode = 'some-fairly-long-URL-to-be-encoded'
after_encode = base58.encode(int.from_bytes(bytes(before_encode, 'utf-8')))
print(before_encode, "- original text")

after_my_encode = base58.encode(my_encode(before_encode))
print(after_my_encode, "- custom encoder then base58\n")
print(after_encode, "- utf8 encoder then base58\n")

# OUTPUT:
# some-fairly-long-URL-to-be-encoded - original text
# 327r1dm63riPzwXmaSSxqARAbVUY6rQ - custom encoder then base58
# 3BmBeSjj7vouzFTw25iM7VUJ7k1jkdgrvHDZLZCYoQUCXjU - utf8 encoder then base58