How to use the hdwallet.hdwallet.HDWallet.from_extended_key function in hdwallet

pub_master_key = master.to_extended_key()



	# 4. On the webserver we can generate child wallets, 
	webserver_wallet = HDWallet.from_extended_key(pub_master_key)
	child2342 = webserver_wallet.child(23).child(42)
	print '- Public Extended Key (M):', pub_master_key
	print 'Child: M/23/42'
	print 'Address:', child2342.address()
	print 'Privkey:', child2342.prvkey() # ... but the private keys remain _unknown_
	print ''


	# 5. In case we need the private key for a child wallet, start with the private master key
	cold_wallet = HDWallet.from_extended_key(prv_master_key)
	child2342 = cold_wallet.child(23).child(42)
	print '- Private Extended Key (m):', prv_master_key
	print 'Child: m/23/42'
	print 'Address:', child2342.address()
	print 'Privkey:', child2342.prvkey().encode('hex')