Remove unused imports. Explicitly import a few deep imports.

lib/wallet.py

@@ -28,18 +28,14 @@
 
 
 import os
-import hashlib
-import ast
 import threading
 import random
 import time
 import json
 import copy
-import re
-import stat
 import errno
 from functools import partial
-from collections import namedtuple, defaultdict
+from collections import defaultdict
 
 from .i18n import _
 from .util import NotEnoughFunds, PrintError, UserCancelled, profiler, format_satoshis
@@ -56,15 +52,12 @@ from . import bitcoin
 from . import coinchooser
 from .synchronizer import Synchronizer
 from .verifier import SPV
-from .mnemonic import Mnemonic
 
 from . import paymentrequest
 from .paymentrequest import PR_PAID, PR_UNPAID, PR_UNKNOWN, PR_EXPIRED
 from .paymentrequest import InvoiceStore
 from .contacts import Contacts
 
-from .storage import WalletStorage
-
 TX_STATUS = [
     _('Replaceable'),
     _('Unconfirmed parent'),
@@ -1281,7 +1274,6 @@ class Abstract_Wallet(PrintError):
         self.storage.put('payment_requests', self.receive_requests)
 
     def add_payment_request(self, req, config):
-        import os
         addr = req['address']
         amount = req.get('amount')
         message = req.get('memo')