define constants for tx output types

plugins/ledger/ledger.py

@@ -5,7 +5,7 @@ from sys import stderr
 from time import sleep
 
 import electrum
-from electrum.bitcoin import EncodeBase58Check, DecodeBase58Check, public_key_to_bc_address, bc_address_to_hash_160
+from electrum.bitcoin import EncodeBase58Check, DecodeBase58Check, public_key_to_bc_address, bc_address_to_hash_160, TYPE_ADDRESS
 from electrum.i18n import _
 from electrum.plugins import BasePlugin, hook
 from electrum.transaction import deserialize
@@ -203,7 +203,7 @@ class BTChipWallet(BIP44_Wallet):
         if len(tx.outputs) > 2: # should never happen
             self.give_error("Transaction with more than 2 outputs not supported")
         for type, address, amount in tx.outputs:
-            assert type == 'address'
+            assert type == TYPE_ADDRESS
             if self.is_change(address):
                 changePath = self.address_id(address)
                 changeAmount = amount

plugins/trezor/plugin.py

@@ -7,7 +7,8 @@ from struct import pack
 
 from electrum.account import BIP32_Account
 from electrum.bitcoin import (bc_address_to_hash_160, xpub_from_pubkey,
-                              public_key_to_bc_address, EncodeBase58Check)
+                              public_key_to_bc_address, EncodeBase58Check,
+                              TYPE_ADDRESS)
 from electrum.i18n import _
 from electrum.plugins import BasePlugin, hook
 from electrum.transaction import (deserialize, is_extended_pubkey,
@@ -427,7 +428,7 @@ class TrezorCompatiblePlugin(BasePlugin, ThreadJob):
         outputs = []
 
         for type, address, amount in tx.outputs:
-            assert type == 'address'
+            assert type == TYPE_ADDRESS
             txoutputtype = self.types.TxOutputType()
             if wallet.is_change(address):
                 address_path = wallet.address_id(address)

plugins/trustedcoin/trustedcoin.py

@@ -234,7 +234,7 @@ class Wallet_2fa(Multisig_Wallet):
         fee = self.extra_fee()
         if fee:
             address = self.billing_info['billing_address']
-            outputs = outputs + [('address', address, fee)]
+            outputs = outputs + [(TYPE_ADDRESS, address, fee)]
             try:
                 return BIP32_Wallet.make_unsigned_transaction(
                     self, coins, outputs, config, fixed_fee, change_addr)