Bit is a fast and compliant Bitcoin library with an extremely easy-to-use API.
Robust API with sane defaults, making development a breeze
Python’s fastest available implementation (100x faster than closest library)
Compliant to many presently implemented Bitcoin Improvement Protocols
All commits require 100% test coverage
Available on all major platforms
Python’s Bitcoin story was pretty bleak. All libraries in use prior to Bit were marred by unfriendly APIs, lack of testing, lack of documentation, lack of cross-platform support, and/or slow implementations.
When I originally went to experiment with sending Bitcoin there were really no good choices. Two choices were out almost immediately: pybitcointools was scary, unpleasant to use, and not very maintained, while python-bitcoinlib, was far too low level. That left pycoin, which was a bit better but still no docs, and 2 libraries from VC funded companies: two1 from 21, which had decent documentation but had an incorrect implementation of the standardized compressed public keys (meaning such keys could literally not spend money), and pybitcoin from Blockstack which did not support Python 3 and had limited docs.
All of these libraries are also slow. Let’s take a look at some common operations.
Instantiate a compressed private key and get its computed public key:
$ python -m timeit -s "from bit import Key" "Key('L3jsepcttyuJK3HKezD4qqRKGtwc8d2d1Nw6vsoPDX9cMcUxqqMv').public_key" 1000 loops, best of 3: 89 usec per loop $ python -m timeit -s "from two1.bitcoin.crypto import PrivateKey" "PrivateKey.from_b58check('L3jsepcttyuJK3HKezD4qqRKGtwc8d2d1Nw6vsoPDX9cMcUxqqMv').public_key.compressed_bytes" 100 loops, best of 3: 11 msec per loop $ python -m timeit -s "from pycoin.key import Key" "Key.from_text('L3jsepcttyuJK3HKezD4qqRKGtwc8d2d1Nw6vsoPDX9cMcUxqqMv').sec()" 10 loops, best of 3: 48.2 msec per loop (py2) >python -m timeit -s "from pybitcoin import BitcoinPrivateKey" "BitcoinPrivateKey('c28a9f80738f770d527803a566cf6fc3edf6cea586c4fc4a5223a5ad797e1ac3').public_key().to_hex()" 10 loops, best of 3: 190 msec per loop
We’ll use two1 only as that was the closest to Bit. Getting the address:
$ python -m timeit -s "from bit import Key;k=Key()" "k.address" 1000000 loops, best of 3: 0.249 usec per loop $ python -m timeit -s "from two1.bitcoin.crypto import PrivateKey;k=PrivateKey.from_random()" "k.public_key.address()" 10000 loops, best of 3: 31.1 usec per loop
Signing, which is the most used operation:
$ python -m timeit -s "from bit import Key;k=Key()" "k.sign(b'data')" 1000 loops, best of 3: 91 usec per loop $ python -m timeit -s "from two1.bitcoin.crypto import PrivateKey;k=PrivateKey.from_random()" "k.raw_sign(b'data')" 100 loops, best of 3: 10.7 msec per loop
The author of pycoin has informed me that a flag can be set on Linux to make some operations faster.