Base 58 Encode

b58encode.py

# From https://datatracker.ietf.org/doc/html/draft-msporny-base58-03
# The description on that page is misleading or just wrong.
# This was derived from converting the Rust code here:
# https://github.com/hachi-bitto/btc-wallet/blob/5dde65a262d3239a23292fc2a4a692994603aeb0/wallet/src/base58.rs

TABLE = "123456789ABCDEFGHJKLMNPQRSTUVWXYZabcdefghijkmnopqrstuvwxyz"

FORWARD = {k:v for (k, v) in enumerate(TABLE)}
BACK = {k:v for (v, k) in enumerate(TABLE)}

def b58_encode(data):
  size = 0
  out = []
  first = True
  for c in data:
    acc = ord(c)
    i = 0
    while acc != 0 or i < size:
      if first:
        out.append(0)
        first = False
      else:
        if i < size:
          acc += out[i] * 256
        else:
          out.append(0)
      acc, out[i] = divmod(acc, 58)
      i += 1
    size = i 
  return ''.join(FORWARD[b] for b in out)

print(b58_encode("Hello World!"))
print(b58_encode("The quick brown fox jumps over the lazy dog."))

# my initial wrong answer
# oGU3JqabjWkQe3