How to use bitcoin-python
Most likely you have not enabled JSON-RPC server in your bitcoin.conf.

You need to have:

# Enable JSON-RPC
server=1

# Username and password
rpcuser=foo
rpcpassword=bar

# This must be enabled for gettransaction() to work
txindex=1


For more information see

http://cryptoassetscore.readthedocs.org/en/latest/backends.html#module-cryptoassets.core.backend.bitcoind