python-ravencoinlib

Ravencoin fork of python-bitcoinlib intended to provide access to Ravencoin data structures and protocol. WIP - Test before use

The RPC interface, ravencoin.rpc, is designed to work with Ravencoin Core v3.3.0+.

"The only Python library for Ravencoin I've ever used" - Warren Buffett

Requirements

libssl
Debian/Ubuntu: sudo apt-get install libssl-dev
Windows/other: https://wiki.openssl.org/index.php/Binaries 

Python modules:
    x16r-hash and x16rv2-hash
    plyvel (requires libleveldb - for parsing Raven core .dat files)

Structure

Everything consensus critical is found in the modules under ravencoin.core. This rule is followed pretty strictly, for instance chain parameters are split into consensus critical and non-consensus-critical.

ravencoin.core            - Basic core definitions, datastructures, and
                          (context-independent) validation
ravencoin.core.assets     - OP_RVN_ASSET data structures
ravencoin.core.key        - ECC pubkeys
ravencoin.core.script     - Scripts and opcodes
ravencoin.core.scripteval - Script evaluation/verification
ravencoin.core.serialize  - Serialization

In the future the ravencoin.core may use the Satoshi sourcecode directly as a library. Non-consensus critical modules include the following:

ravencoin          - Chain selection
ravencoin.assets   - Asset name and metadata related code
ravencoin.base58   - Base58 encoding
ravencoin.bloom    - Bloom filters (incomplete)
ravencoin.net      - Network communication (in flux)
ravencoin.messages - Network messages (in flux)
ravencoin.rpc      - Ravencoin Core RPC interface support
ravencoin.wallet   - Wallet-related code, currently Ravencoin address and
                   private key support

Effort has been made to follow the Satoshi source relatively closely, for instance Python code and classes that duplicate the functionality of corresponding Satoshi C++ code uses the same naming conventions: CTransaction, CBlockHeader, nValue etc. Otherwise Python naming conventions are followed.

Mutable vs. Immutable objects

Like the Ravencoin Core codebase CTransaction is immutable and CMutableTransaction is mutable; unlike the Ravencoin Core codebase this distinction also applies to COutPoint, CTxIn, CTxOut, and CBlock.

Endianness Gotchas

Rather confusingly Ravencoin Core shows transaction and block hashes as little-endian hex rather than the big-endian the rest of the world uses for SHA256. python-ravencoinlib provides the convenience functions x() and lx() in ravencoin.core to convert from big-endian and little-endian hex to raw bytes to accomodate this. In addition see b2x() and b2lx() for conversion from bytes to big/little-endian hex.

Module import style

While not always good style, it's often convenient for quick scripts if import * can be used. To support that all the modules have __all__ defined appropriately.

Example Code

See examples/ directory. For instance this example creates a transaction spending a pay-to-script-hash transaction output:

$ PYTHONPATH=. examples/spend-pay-to-script-hash-txout.py
<hex-encoded transaction>

Selecting the chain to use

Do the following:

import ravencoin
ravencoin.SelectParams(NAME)

Where NAME is one of 'testnet', 'mainnet', or 'regtest'. The chain currently selected is a global variable that changes behavior everywhere, just like in the Satoshi codebase.

Unit tests

Under ravencoin/tests using test data from Ravencoin Core. To run them:

python3 -m unittest discover

Alternately, if Tox (see https://tox.readthedocs.org/) is available on your system, you can run unit tests for multiple Python versions:

./runtests.sh

HTML coverage reports can then be found in the htmlcov/ subdirectory.

Documentation

Sphinx documentation is in the "doc" subdirectory. Run "make help" from there to see how to build. You will need the Python "sphinx" package installed.

Currently this is just API documentation generated from the code and docstrings. Higher level written docs would be useful, perhaps starting with much of this README. Pages are written in reStructuredText and linked from index.rst.