Package: pycoin
pycoin -- Python Cryptocoin UtilitiesThe pycoin library implements many utilities useful when dealing with bitcoin and some bitcoin-like
alt-coins. It has been tested with Python 2.7, 3.6 and 3.7.See alsopycoinnetfor a library that speaks the bitcoin protocol.Documentation atreadthedocsDiscussion atzulipchatNetworksAs of 0.9, pycoin supports many coins to various degrees via the "network" class. Since specifications
vary based on the network (for example, bitcoin mainnet addresses start with a "1", but testnet
addresses start with an "m" or "n"), all API descends from a network object. Everything related to a
particular network is scoped under this class.Bitcoin has the highest level of support, including keys, transactions, validation of signed transactions, and
signing unsigned transactions, including partial signing of multisig transactions. These are in level of
increasing complexity, so features for other coins will likely be supported in that order.There are two main ways to get a network:from pycoin.symbols.btc import networkORfrom pycoin.networks.registry import network_for_netcode
network = network_for_netcode("BTC")KeysYou can create a private key and get the corresponding address.from pycoin.symbols.btc import network

key = network.keys.private(secret_exponent=1)  # this is a terrible key because it's very guessable
print(key.wif())
print(key.sec())
print(key.address())
print(key.address(is_compressed=False))

same_key = network.parse.private(key.wif())
print(same_key.address())BIP32You can create a BIP32 key.key = network.keys.bip32_seed(b"foo")  # this is a terrible key because it's very guessable
print(key.hwif(as_private=1))
print(key.hwif())
print(key.wif())
print(key.sec())
print(key.address())You can parse a BIP32 key.key = network.parse.bip32("xprv9s21ZrQH143K31AgNK5pyVvW23gHnkBq2wh5aEk6g1s496M"
      "8ZMjxncCKZKgb5jZoY5eSJMJ2Vbyvi2hbmQnCuHBujZ2WXGTux1X2k9Krdtq")
print(key.hwif(as_private=1))
print(key.hwif())
print(key.wif())
print(key.sec())
print(key.address())WARNING: be extremely careful giving out public wallet keys. If someone has access to a private wallet key P, of
course they have access to all descendent wallet keys of P. But if they also have access to a public wallet key K
where P is a subkey of K, you can actually work your way up the tree to determine the private key that corresponds
to the public wallet key K (unless private derivation was used at some point between the two keys)! Be sure you
understand this warning before giving out public wallet keys!Much of this API is exposed in thekucommand-line utility. See alsoCOMMAND-LINE-TOOLS.md.SeeBIP32.txtfor more information.TransactionsThe command-line utilitytxis a Swiss Army knife of transaction utilities. See alsoCOMMAND-LINE-TOOLS.md.ServicesWhen signing or verifying signatures on a transaction, the source transactions are generally needed. If you set two
environment variables in your.profilelike this:PYCOIN_CACHE_DIR=~/.pycoin_cache
PYCOIN_BTC_PROVIDERS="blockchain.info blockexplorer.com chain.so"
export PYCOIN_CACHE_DIR PYCOIN_BTC_PROVIDERS
export PYCOIN_XTN_PROVIDERS="blockchain.info"  # For Bitcoin testnetand thentxwill automatically fetch transactions from the web sites listed and cache the results inPYCOIN_CACHE_DIRwhen they are needed.(The old syntax withPYCOIN_SERVICE_PROVIDERSis deprecated.)The module pycoin.services includes two functionsspendables_for_address,get_tx_dbthat look at the
environment variables set to determine which web sites to use to fetch the underlying information. The sites are
polled in the order they are listed in the environment variable.BlocksThe command-line utilityblockwill dump a block in a human-readable format. For further information, look atpycoin.block, which includes the objectBlockwhich will parse and stream the binary format of a block.ECDSA Signing and VerificationThe modulepycoin.ecdsadeals with ECDSA keys directly. Important structures include:thesecret_exponent(a large integer that represents a private key)thepublic_pair(a pair of large integers x and y that represent a public key)There are a handful of functions: you can do things like create a signature, verify a signature, generate the public
pair from the secret exponent, and flush out the public pair from just the x value (there are two possible values
for y of opposite even/odd parity, so you include a flag indicating which value for y you want).Thepycoin.ecdsa.nativemodule looks for both OpenSSL and libsecp256k1 (with hints fromPYCOIN_LIBCRYPTO_PATHandPYCOIN_LIBSECP256K1_PATH) and calls out to these libraries if
they are present to accelerate ecdsa operations. SetPYCOIN_NATIVEtoopenssl,secp256k1ornoneto tweak this.Example:$ PYCOIN_NATIVE=openssl
$ export PYCOIN_NATIVEDonateWant to donate? Feel free. Send to 1KissZi1jr5eD7Rb9fepRHiS4ur2hc9PwS.
I'm also available for bitcoin consulting...him@richardkiss.com.BIP0032