diff --git a/test/functional/abc-p2p-fullblocktest.py b/test/functional/abc-p2p-fullblocktest.py
--- a/test/functional/abc-p2p-fullblocktest.py
+++ b/test/functional/abc-p2p-fullblocktest.py
@@ -22,7 +22,7 @@
                                   MAX_BLOCK_SIGOPS_PER_MB, MAX_TX_SIGOPS_COUNT)
 
 
-class PreviousSpendableOutput(object):
+class PreviousSpendableOutput():
 
     def __init__(self, tx=CTransaction(), n=-1):
         self.tx = tx
diff --git a/test/functional/mempool-accept-txn.py b/test/functional/mempool-accept-txn.py
--- a/test/functional/mempool-accept-txn.py
+++ b/test/functional/mempool-accept-txn.py
@@ -24,7 +24,7 @@
     TXNS_TOO_MANY_SIGOPS_ERROR.decode("utf-8")
 
 
-class PreviousSpendableOutput(object):
+class PreviousSpendableOutput():
 
     def __init__(self, tx=CTransaction(), n=-1):
         self.tx = tx
diff --git a/test/functional/p2p-fullblocktest.py b/test/functional/p2p-fullblocktest.py
--- a/test/functional/p2p-fullblocktest.py
+++ b/test/functional/p2p-fullblocktest.py
@@ -15,8 +15,7 @@
 from test_framework.cdefs import LEGACY_MAX_BLOCK_SIZE, MAX_BLOCK_SIGOPS_PER_MB
 
 
-class PreviousSpendableOutput(object):
-
+class PreviousSpendableOutput():
     def __init__(self, tx=CTransaction(), n=-1):
         self.tx = tx
         self.n = n  # the output we're spending
diff --git a/test/functional/test_framework/authproxy.py b/test/functional/test_framework/authproxy.py
--- a/test/functional/test_framework/authproxy.py
+++ b/test/functional/test_framework/authproxy.py
@@ -34,24 +34,17 @@
   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 """
 
-try:
-    import http.client as httplib
-except ImportError:
-    import httplib
 import base64
 import decimal
+import http.client
 import json
 import logging
 import socket
 import time
-try:
-    import urllib.parse as urlparse
-except ImportError:
-    import urlparse
-
-USER_AGENT = "AuthServiceProxy/0.1"
+import urllib.parse
 
 HTTP_TIMEOUT = 30
+USER_AGENT = "AuthServiceProxy/0.1"
 
 log = logging.getLogger("BitcoinRPC")
 
@@ -62,7 +55,7 @@
             errmsg = '%(message)s (%(code)i)' % rpc_error
         except (KeyError, TypeError):
             errmsg = ''
-        Exception.__init__(self, errmsg)
+        super().__init__(errmsg)
         self.error = rpc_error
 
 
@@ -72,7 +65,7 @@
     raise TypeError(repr(o) + " is not JSON serializable")
 
 
-class AuthServiceProxy(object):
+class AuthServiceProxy():
     __id_count = 0
 
     # ensure_ascii: escape unicode as \uXXXX, passed to json.dumps
@@ -80,20 +73,12 @@
         self.__service_url = service_url
         self._service_name = service_name
         self.ensure_ascii = ensure_ascii  # can be toggled on the fly by tests
-        self.__url = urlparse.urlparse(service_url)
-        if self.__url.port is None:
-            port = 80
-        else:
-            port = self.__url.port
-        (user, passwd) = (self.__url.username, self.__url.password)
-        try:
-            user = user.encode('utf8')
-        except AttributeError:
-            pass
-        try:
-            passwd = passwd.encode('utf8')
-        except AttributeError:
-            pass
+        self.__url = urllib.parse.urlparse(service_url)
+        port = 80 if self.__url.port is None else self.__url.port
+        user = None if self.__url.username is None else self.__url.username.encode(
+            'utf8')
+        passwd = None if self.__url.password is None else self.__url.password.encode(
+            'utf8')
         authpair = user + b':' + passwd
         self.__auth_header = b'Basic ' + base64.b64encode(authpair)
 
@@ -101,11 +86,11 @@
             # Callables re-use the connection of the original proxy
             self.__conn = connection
         elif self.__url.scheme == 'https':
-            self.__conn = httplib.HTTPSConnection(self.__url.hostname, port,
-                                                  timeout=timeout)
+            self.__conn = http.client.HTTPSConnection(
+                self.__url.hostname, port, timeout=timeout)
         else:
-            self.__conn = httplib.HTTPConnection(self.__url.hostname, port,
-                                                 timeout=timeout)
+            self.__conn = http.client.HTTPConnection(
+                self.__url.hostname, port, timeout=timeout)
 
     def __getattr__(self, name):
         if name.startswith('__') and name.endswith('__'):
@@ -127,7 +112,7 @@
         try:
             self.__conn.request(method, path, postdata, headers)
             return self._get_response()
-        except httplib.BadStatusLine as e:
+        except http.client.BadStatusLine as e:
             if e.line == "''":  # if connection was closed, try again
                 self.__conn.close()
                 self.__conn.request(method, path, postdata, headers)
@@ -163,7 +148,7 @@
         else:
             return response['result']
 
-    def _batch(self, rpc_call_list):
+    def batch(self, rpc_call_list):
         postdata = json.dumps(
             list(rpc_call_list), default=EncodeDecimal, ensure_ascii=self.ensure_ascii)
         log.debug("--> " + postdata)
diff --git a/test/functional/test_framework/blockstore.py b/test/functional/test_framework/blockstore.py
--- a/test/functional/test_framework/blockstore.py
+++ b/test/functional/test_framework/blockstore.py
@@ -2,10 +2,7 @@
 # Copyright (c) 2015-2016 The Bitcoin Core developers
 # Distributed under the MIT software license, see the accompanying
 # file COPYING or http://www.opensource.org/licenses/mit-license.php.
-# BlockStore: a helper class that keeps a map of blocks and implements
-#             helper functions for responding to getheaders and getdata,
-#             and for constructing a getheaders message
-#
+"""BlockStore and TxStore helper classes."""
 
 from .mininode import *
 from io import BytesIO
@@ -14,7 +11,13 @@
 logger = logging.getLogger("TestFramework.blockstore")
 
 
-class BlockStore(object):
+class BlockStore():
+    """BlockStore helper class.
+
+    BlockStore keeps a map of blocks and implements helper functions for
+    responding to getheaders and getdata, and for constructing a getheaders
+    message.
+    """
 
     def __init__(self, datadir):
         self.blockDB = dbmd.open(datadir + "/blocks", 'c')
@@ -126,8 +129,7 @@
         return locator
 
 
-class TxStore(object):
-
+class TxStore():
     def __init__(self, datadir):
         self.txDB = dbmd.open(datadir + "/transactions", 'c')
 
diff --git a/test/functional/test_framework/comptool.py b/test/functional/test_framework/comptool.py
--- a/test/functional/test_framework/comptool.py
+++ b/test/functional/test_framework/comptool.py
@@ -31,11 +31,8 @@
 global mininode_lock
 
 
-class RejectResult(object):
-
-    '''
-    Outcome that expects rejection of a transaction or block.
-    '''
+class RejectResult():
+    """Outcome that expects rejection of a transaction or block."""
 
     def __init__(self, code, reason=b''):
         self.code = code
@@ -174,16 +171,14 @@
 #    or false, then only the last tx is tested against outcome.)
 
 
-class TestInstance(object):
-
+class TestInstance():
     def __init__(self, objects=None, sync_every_block=True, sync_every_tx=False):
         self.blocks_and_transactions = objects if objects else []
         self.sync_every_block = sync_every_block
         self.sync_every_tx = sync_every_tx
 
 
-class TestManager(object):
-
+class TestManager():
     def __init__(self, testgen, datadir):
         self.test_generator = testgen
         self.connections = []
diff --git a/test/functional/test_framework/coverage.py b/test/functional/test_framework/coverage.py
--- a/test/functional/test_framework/coverage.py
+++ b/test/functional/test_framework/coverage.py
@@ -17,7 +17,7 @@
 REFERENCE_FILENAME = 'rpc_interface.txt'
 
 
-class AuthServiceProxyWrapper(object):
+class AuthServiceProxyWrapper():
     """
     An object that wraps AuthServiceProxy to record specific RPC calls.
 
diff --git a/test/functional/test_framework/key.py b/test/functional/test_framework/key.py
--- a/test/functional/test_framework/key.py
+++ b/test/functional/test_framework/key.py
@@ -96,7 +96,7 @@
 ssl.EC_KEY_new_by_curve_name.errcheck = _check_result
 
 
-class CECKey(object):
+class CECKey():
     """Wrapper around OpenSSL's EC_KEY"""
 
     POINT_CONVERSION_COMPRESSED = 2
diff --git a/test/functional/test_framework/mininode.py b/test/functional/test_framework/mininode.py
--- a/test/functional/test_framework/mininode.py
+++ b/test/functional/test_framework/mininode.py
@@ -239,8 +239,7 @@
 # Objects that map to bitcoind objects, which can be serialized/deserialized
 
 
-class CAddress(object):
-
+class CAddress():
     def __init__(self):
         self.nServices = 1
         self.pchReserved = b"\x00" * 10 + b"\xff" * 2
@@ -269,7 +268,7 @@
 MSG_WITNESS_FLAG = 1 << 30
 
 
-class CInv(object):
+class CInv():
     typemap = {
         0: "Error",
         1: "TX",
@@ -298,8 +297,7 @@
             % (self.typemap[self.type], self.hash)
 
 
-class CBlockLocator(object):
-
+class CBlockLocator():
     def __init__(self):
         self.nVersion = MY_VERSION
         self.vHave = []
@@ -319,8 +317,7 @@
             % (self.nVersion, repr(self.vHave))
 
 
-class COutPoint(object):
-
+class COutPoint():
     def __init__(self, hash=0, n=0):
         self.hash = hash
         self.n = n
@@ -339,8 +336,7 @@
         return "COutPoint(hash=%064x n=%i)" % (self.hash, self.n)
 
 
-class CTxIn(object):
-
+class CTxIn():
     def __init__(self, outpoint=None, scriptSig=b"", nSequence=0):
         if outpoint is None:
             self.prevout = COutPoint()
@@ -368,8 +364,7 @@
                self.nSequence)
 
 
-class CTxOut(object):
-
+class CTxOut():
     def __init__(self, nValue=0, scriptPubKey=b""):
         self.nValue = nValue
         self.scriptPubKey = scriptPubKey
@@ -390,8 +385,7 @@
                bytes_to_hex_str(self.scriptPubKey))
 
 
-class CScriptWitness(object):
-
+class CScriptWitness():
     def __init__(self):
         # stack is a vector of strings
         self.stack = []
@@ -406,8 +400,7 @@
         return True
 
 
-class CTxInWitness(object):
-
+class CTxInWitness():
     def __init__(self):
         self.scriptWitness = CScriptWitness()
 
@@ -424,8 +417,7 @@
         return self.scriptWitness.is_null()
 
 
-class CTxWitness(object):
-
+class CTxWitness():
     def __init__(self):
         self.vtxinwit = []
 
@@ -453,8 +445,7 @@
         return True
 
 
-class CTransaction(object):
-
+class CTransaction():
     def __init__(self, tx=None):
         if tx is None:
             self.nVersion = 1
@@ -559,8 +550,7 @@
             % (self.nVersion, repr(self.vin), repr(self.vout), repr(self.wit), self.nLockTime)
 
 
-class CBlockHeader(object):
-
+class CBlockHeader():
     def __init__(self, header=None):
         if header is None:
             self.set_null()
@@ -700,8 +690,7 @@
                time.ctime(self.nTime), self.nBits, self.nNonce, repr(self.vtx))
 
 
-class CUnsignedAlert(object):
-
+class CUnsignedAlert():
     def __init__(self):
         self.nVersion = 1
         self.nRelayUntil = 0
@@ -756,8 +745,7 @@
                self.strComment, self.strStatusBar, self.strReserved)
 
 
-class CAlert(object):
-
+class CAlert():
     def __init__(self):
         self.vchMsg = b""
         self.vchSig = b""
@@ -777,8 +765,7 @@
             % (len(self.vchMsg), len(self.vchSig))
 
 
-class PrefilledTransaction(object):
-
+class PrefilledTransaction():
     def __init__(self, index=0, tx=None):
         self.index = index
         self.tx = tx
@@ -806,8 +793,7 @@
 # This is what we send on the wire, in a cmpctblock message.
 
 
-class P2PHeaderAndShortIDs(object):
-
+class P2PHeaderAndShortIDs():
     def __init__(self):
         self.header = CBlockHeader()
         self.nonce = 0
@@ -867,8 +853,7 @@
 # encoding into indices that can be used for lookup.
 
 
-class HeaderAndShortIDs(object):
-
+class HeaderAndShortIDs():
     def __init__(self, p2pheaders_and_shortids=None):
         self.header = CBlockHeader()
         self.nonce = 0
@@ -932,7 +917,7 @@
         return "HeaderAndShortIDs(header=%s, nonce=%d, shortids=%s, prefilledtxn=%s" % (repr(self.header), self.nonce, repr(self.shortids), repr(self.prefilled_txn))
 
 
-class BlockTransactionsRequest(object):
+class BlockTransactionsRequest():
 
     def __init__(self, blockhash=0, indexes=None):
         self.blockhash = blockhash
@@ -972,7 +957,7 @@
         return "BlockTransactionsRequest(hash=%064x indexes=%s)" % (self.blockhash, repr(self.indexes))
 
 
-class BlockTransactions(object):
+class BlockTransactions():
 
     def __init__(self, blockhash=0, transactions=None):
         self.blockhash = blockhash
@@ -996,7 +981,7 @@
 
 
 # Objects that correspond to messages on the wire
-class msg_version(object):
+class msg_version():
     command = b"version"
 
     def __init__(self):
@@ -1064,7 +1049,7 @@
                self.strSubVer, self.nStartingHeight, self.nRelay)
 
 
-class msg_verack(object):
+class msg_verack():
     command = b"verack"
 
     def __init__(self):
@@ -1080,7 +1065,7 @@
         return "msg_verack()"
 
 
-class msg_addr(object):
+class msg_addr():
     command = b"addr"
 
     def __init__(self):
@@ -1096,7 +1081,7 @@
         return "msg_addr(addrs=%s)" % (repr(self.addrs))
 
 
-class msg_alert(object):
+class msg_alert():
     command = b"alert"
 
     def __init__(self):
@@ -1115,7 +1100,7 @@
         return "msg_alert(alert=%s)" % (repr(self.alert), )
 
 
-class msg_inv(object):
+class msg_inv():
     command = b"inv"
 
     def __init__(self, inv=None):
@@ -1134,7 +1119,7 @@
         return "msg_inv(inv=%s)" % (repr(self.inv))
 
 
-class msg_getdata(object):
+class msg_getdata():
     command = b"getdata"
 
     def __init__(self, inv=None):
@@ -1150,7 +1135,7 @@
         return "msg_getdata(inv=%s)" % (repr(self.inv))
 
 
-class msg_getblocks(object):
+class msg_getblocks():
     command = b"getblocks"
 
     def __init__(self):
@@ -1173,7 +1158,7 @@
             % (repr(self.locator), self.hashstop)
 
 
-class msg_tx(object):
+class msg_tx():
     command = b"tx"
 
     def __init__(self, tx=CTransaction()):
@@ -1195,7 +1180,7 @@
         return self.tx.serialize_with_witness()
 
 
-class msg_block(object):
+class msg_block():
     command = b"block"
 
     def __init__(self, block=None):
@@ -1217,8 +1202,7 @@
 # note that the user must supply the name of the command, and the data
 
 
-class msg_generic(object):
-
+class msg_generic():
     def __init__(self, command, data=None):
         self.command = command
         self.data = data
@@ -1237,7 +1221,7 @@
         return r
 
 
-class msg_getaddr(object):
+class msg_getaddr():
     command = b"getaddr"
 
     def __init__(self):
@@ -1253,7 +1237,7 @@
         return "msg_getaddr()"
 
 
-class msg_ping_prebip31(object):
+class msg_ping_prebip31():
     command = b"ping"
 
     def __init__(self):
@@ -1269,7 +1253,7 @@
         return "msg_ping() (pre-bip31)"
 
 
-class msg_ping(object):
+class msg_ping():
     command = b"ping"
 
     def __init__(self, nonce=0):
@@ -1287,7 +1271,7 @@
         return "msg_ping(nonce=%08x)" % self.nonce
 
 
-class msg_pong(object):
+class msg_pong():
     command = b"pong"
 
     def __init__(self, nonce=0):
@@ -1305,7 +1289,7 @@
         return "msg_pong(nonce=%08x)" % self.nonce
 
 
-class msg_mempool(object):
+class msg_mempool():
     command = b"mempool"
 
     def __init__(self):
@@ -1321,7 +1305,7 @@
         return "msg_mempool()"
 
 
-class msg_sendheaders(object):
+class msg_sendheaders():
     command = b"sendheaders"
 
     def __init__(self):
@@ -1341,7 +1325,7 @@
 # number of entries
 # vector of hashes
 # hash_stop (hash of last desired block header, 0 to get as many as possible)
-class msg_getheaders(object):
+class msg_getheaders():
     command = b"getheaders"
 
     def __init__(self):
@@ -1366,7 +1350,7 @@
 
 # headers message has
 # <count> <vector of block headers>
-class msg_headers(object):
+class msg_headers():
     command = b"headers"
 
     def __init__(self):
@@ -1386,7 +1370,7 @@
         return "msg_headers(headers=%s)" % repr(self.headers)
 
 
-class msg_reject(object):
+class msg_reject():
     command = b"reject"
     REJECT_MALFORMED = 1
 
@@ -1417,10 +1401,11 @@
         return "msg_reject: %s %d %s [%064x]" \
             % (self.message, self.code, self.reason, self.data)
 
-# Helper function
-
 
 def wait_until(predicate, *, attempts=float('inf'), timeout=float('inf')):
+    '''
+    This function is subsequently remove in core's PR11712
+    '''
     attempt = 0
     elapsed = 0
 
@@ -1435,7 +1420,7 @@
     return False
 
 
-class msg_feefilter(object):
+class msg_feefilter():
     command = b"feefilter"
 
     def __init__(self, feerate=0):
@@ -1453,7 +1438,7 @@
         return "msg_feefilter(feerate=%08x)" % self.feerate
 
 
-class msg_sendcmpct(object):
+class msg_sendcmpct():
     command = b"sendcmpct"
 
     def __init__(self):
@@ -1474,7 +1459,7 @@
         return "msg_sendcmpct(announce=%s, version=%lu)" % (self.announce, self.version)
 
 
-class msg_cmpctblock(object):
+class msg_cmpctblock():
     command = b"cmpctblock"
 
     def __init__(self, header_and_shortids=None):
@@ -1493,7 +1478,7 @@
         return "msg_cmpctblock(HeaderAndShortIDs=%s)" % repr(self.header_and_shortids)
 
 
-class msg_getblocktxn(object):
+class msg_getblocktxn():
     command = b"getblocktxn"
 
     def __init__(self):
@@ -1512,7 +1497,7 @@
         return "msg_getblocktxn(block_txn_request=%s)" % (repr(self.block_txn_request))
 
 
-class msg_blocktxn(object):
+class msg_blocktxn():
     command = b"blocktxn"
 
     def __init__(self):
@@ -1538,7 +1523,7 @@
         return r
 
 
-class NodeConnCB(object):
+class NodeConnCB():
     """Callback and helper functions for P2P connection to a bitcoind node.
 
     Individual testcases should subclass this and override the on_* methods
diff --git a/test/functional/test_framework/script.py b/test/functional/test_framework/script.py
--- a/test/functional/test_framework/script.py
+++ b/test/functional/test_framework/script.py
@@ -635,7 +635,7 @@
 # This is used, eg, for blockchain heights in coinbase scripts (bip34)
 
 
-class CScriptNum(object):
+class CScriptNum():
     def __init__(self, d=0):
         self.value = d
 
diff --git a/test/functional/test_framework/socks5.py b/test/functional/test_framework/socks5.py
--- a/test/functional/test_framework/socks5.py
+++ b/test/functional/test_framework/socks5.py
@@ -41,8 +41,8 @@
 # Implementation classes
 
 
-class Socks5Configuration(object):
-    '''Proxy configuration'''
+class Socks5Configuration():
+    """Proxy configuration."""
 
     def __init__(self):
         self.addr = None  # Bind address (must be set)
@@ -51,8 +51,8 @@
         self.auth = False  # Support authentication
 
 
-class Socks5Command(object):
-    '''Information about an incoming socks5 command'''
+class Socks5Command():
+    """Information about an incoming socks5 command."""
 
     def __init__(self, cmd, atyp, addr, port, username, password):
         self.cmd = cmd  # Command (one of Command.*)
@@ -66,7 +66,7 @@
         return 'Socks5Command(%s,%s,%s,%s,%s,%s)' % (self.cmd, self.atyp, self.addr, self.port, self.username, self.password)
 
 
-class Socks5Connection(object):
+class Socks5Connection():
     def __init__(self, serv, conn, peer):
         self.serv = serv
         self.conn = conn
@@ -142,7 +142,7 @@
             self.conn.close()
 
 
-class Socks5Server(object):
+class Socks5Server():
     def __init__(self, conf):
         self.conf = conf
         self.s = socket.socket(conf.af)
diff --git a/test/functional/test_framework/test_framework.py b/test/functional/test_framework/test_framework.py
--- a/test/functional/test_framework/test_framework.py
+++ b/test/functional/test_framework/test_framework.py
@@ -51,7 +51,7 @@
 BITCOIND_PROC_WAIT_TIMEOUT = 60
 
 
-class BitcoinTestFramework(object):
+class BitcoinTestFramework():
     """Base class for a bitcoin test script.
 
     Individual bitcoin test scripts should subclass this class and override the following methods:
diff --git a/test/functional/test_runner.py b/test/functional/test_runner.py
--- a/test/functional/test_runner.py
+++ b/test/functional/test_runner.py
@@ -479,8 +479,7 @@
             sys.exit(1)
 
 
-class RPCCoverage(object):
-
+class RPCCoverage():
     """
     Coverage reporting utilities for test_runner.