Support generate keys from account extend public key.

[Deleted user]

Currencty, bip32 object is encapsulated in the Wallet class as a private property which could only instantiate from mnemonic. If we can provide some ways to allow client instantiate bip32 object from other source such as xpub, this can offer more flexibility to this library. How do you think? If you have the plan, I would be happy to work on it and submit a PR if I can.

[kigawas]

Good idea, but if you don't need the mnemonic, maybe python-bip32 would be more appropriate to your needs.