Skip to content

Instantly share code, notes, and snippets.

@clayrichardson
Forked from ianoxley/base58.py
Created June 30, 2013 11:14
Show Gist options
  • Save clayrichardson/5894793 to your computer and use it in GitHub Desktop.
Save clayrichardson/5894793 to your computer and use it in GitHub Desktop.
""" base58 encoding / decoding functions """
import unittest
alphabet = '123456789abcdefghijkmnopqrstuvwxyzABCDEFGHJKLMNPQRSTUVWXYZ'
base_count = len(alphabet)
def encode(num):
""" Returns num in a base58-encoded string """
encode = ''
if (num < 0):
return ''
while (num >= base_count):
mod = num % base_count
encode = alphabet[mod] + encode
num = num / base_count
if (num):
encode = alphabet[num] + encode
return encode
def decode(s):
""" Decodes the base58-encoded string s into an integer """
decoded = 0
multi = 1
s = s[::-1]
for char in s:
decoded += multi * alphabet.index(char)
multi = multi * base_count
return decoded
class Base58Tests(unittest.TestCase):
def test_alphabet_length(self):
self.assertEqual(58, len(alphabet))
def test_encode_10002343_returns_Tgmc(self):
result = encode(10002343)
self.assertEqual('Tgmc', result)
def test_decode_Tgmc_returns_10002343(self):
decoded = decode('Tgmc')
self.assertEqual(10002343, decoded)
def test_encode_1000_returns_if(self):
result = encode(1000)
self.assertEqual('if', result)
def test_decode_if_returns_1000(self):
decoded = decode('if')
self.assertEqual(1000, decoded)
def test_encode_zero_returns_empty_string(self):
self.assertEqual('', encode(0))
def test_encode_negative_number_returns_empty_string(self):
self.assertEqual('', encode(-100))
if __name__ == '__main__':
unittest.main()
Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment