diff --git a/.arclint b/.arclint
--- a/.arclint
+++ b/.arclint
@@ -24,7 +24,7 @@
             "type": "flake8",
             "include": "(\\.py$)",
             "flags": [
-                "--select=E112,E113,E115,E116,E125,E131,E133,E223,E224,E242,E266,E271,E272,E273,E274,E275,E304,E306,E401,E402,E502,E701,E702,E703,E714,E721,E741,E742,E743,E901,E902,F401,F402,F403,F404,F405,F406,F407,F601,F602,F621,F622,F631,F701,F702,F703,F704,F705,F706,F707,F811,F812,F821,F822,F823,F831,F841,W292,W293,W601,W602,W603,W604,W605,W606"
+                "--select=E112,E113,E115,E116,E125,E131,E133,E223,E224,E242,E266,E271,E272,E273,E274,E275,E304,E306,E401,E402,E502,E701,E702,E703,E711,E714,E721,E741,E742,E743,E901,E902,F401,F402,F403,F404,F405,F406,F407,F601,F602,F621,F622,F631,F701,F702,F703,F704,F705,F706,F707,F811,F812,F821,F822,F823,F831,F841,W292,W293,W601,W602,W603,W604,W605,W606"
             ]
         },
         "lint-format-strings": {
diff --git a/contrib/devtools/copyright_header.py b/contrib/devtools/copyright_header.py
--- a/contrib/devtools/copyright_header.py
+++ b/contrib/devtools/copyright_header.py
@@ -538,7 +538,7 @@
 
 def file_already_has_bitcoin_copyright(file_lines):
     index, _ = get_updatable_copyright_line(file_lines)
-    return index != None
+    return index is not None
 
 ################################################################################
 # insert header execution
diff --git a/test/functional/abc-invalid-chains.py b/test/functional/abc-invalid-chains.py
--- a/test/functional/abc-invalid-chains.py
+++ b/test/functional/abc-invalid-chains.py
@@ -24,7 +24,7 @@
         self.extra_args = [["-whitelist=127.0.0.1"]]
 
     def next_block(self, number):
-        if self.tip == None:
+        if self.tip is None:
             base_block_hash = self.genesis_hash
             block_time = int(time.time()) + 1
         else:
diff --git a/test/functional/abc-mempool-accept-txn.py b/test/functional/abc-mempool-accept-txn.py
--- a/test/functional/abc-mempool-accept-txn.py
+++ b/test/functional/abc-mempool-accept-txn.py
@@ -104,7 +104,7 @@
         return tx
 
     def next_block(self, number, spend=None, additional_coinbase_value=0, script=CScript([OP_TRUE])):
-        if self.tip == None:
+        if self.tip is None:
             base_block_hash = self.genesis_hash
             block_time = int(time.time()) + 1
         else:
@@ -115,7 +115,7 @@
         coinbase = create_coinbase(height, self.coinbase_pubkey)
         coinbase.vout[0].nValue += additional_coinbase_value
         coinbase.rehash()
-        if spend == None:
+        if spend is None:
             block = create_block(base_block_hash, coinbase, block_time)
         else:
             # all but one satoshi to fees
diff --git a/test/functional/abc-mempool-coherence-on-activations.py b/test/functional/abc-mempool-coherence-on-activations.py
--- a/test/functional/abc-mempool-coherence-on-activations.py
+++ b/test/functional/abc-mempool-coherence-on-activations.py
@@ -132,7 +132,7 @@
                             EXTRA_ARG]]
 
     def next_block(self, number):
-        if self.tip == None:
+        if self.tip is None:
             base_block_hash = self.genesis_hash
             block_time = FIRST_BLOCK_TIME
         else:
diff --git a/test/functional/abc-p2p-compactblocks.py b/test/functional/abc-p2p-compactblocks.py
--- a/test/functional/abc-p2p-compactblocks.py
+++ b/test/functional/abc-p2p-compactblocks.py
@@ -116,7 +116,7 @@
         return tx
 
     def next_block(self, number, spend=None, script=CScript([OP_TRUE]), block_size=0, extra_txns=0):
-        if self.tip == None:
+        if self.tip is None:
             base_block_hash = self.genesis_hash
             block_time = int(time.time()) + 1
         else:
@@ -126,7 +126,7 @@
         height = self.block_heights[base_block_hash] + 1
         coinbase = create_coinbase(height)
         coinbase.rehash()
-        if spend == None:
+        if spend is None:
             # We need to have something to spend to fill the block.
             assert_equal(block_size, 0)
             block = create_block(base_block_hash, coinbase, block_time)
@@ -159,7 +159,7 @@
             tx.rehash()
 
             # If a specific script is required, add it.
-            if script != None:
+            if script is not None:
                 tx.vout.append(CTxOut(1, script))
 
             # Put some random data into the first transaction of the chain to randomize ids.
@@ -278,7 +278,7 @@
         # Check that compact block also work for big blocks
         # Wait for SENDCMPCT
         def received_sendcmpct():
-            return (test_p2p.last_sendcmpct != None)
+            return (test_p2p.last_sendcmpct is not None)
         wait_until(received_sendcmpct, timeout=30)
 
         sendcmpct = msg_sendcmpct()
@@ -288,7 +288,7 @@
 
         # Exchange headers
         def received_getheaders():
-            return (test_p2p.last_getheaders != None)
+            return (test_p2p.last_getheaders is not None)
         wait_until(received_getheaders, timeout=30)
 
         # Return the favor
@@ -296,7 +296,7 @@
 
         # Wait for the header list
         def received_headers():
-            return (test_p2p.last_headers != None)
+            return (test_p2p.last_headers is not None)
         wait_until(received_headers, timeout=30)
 
         # It's like we know about the same headers !
@@ -308,7 +308,7 @@
 
         # Checks the node to forward it via compact block
         def received_block():
-            return (test_p2p.last_cmpctblock != None)
+            return (test_p2p.last_cmpctblock is not None)
         wait_until(received_block, timeout=30)
 
         # Was it our block ?
diff --git a/test/functional/abc-p2p-fullblocktest-sigops.py b/test/functional/abc-p2p-fullblocktest-sigops.py
--- a/test/functional/abc-p2p-fullblocktest-sigops.py
+++ b/test/functional/abc-p2p-fullblocktest-sigops.py
@@ -90,7 +90,7 @@
         return tx
 
     def next_block(self, number, spend=None, script=CScript([OP_TRUE]), block_size=0, extra_sigops=0):
-        if self.tip == None:
+        if self.tip is None:
             base_block_hash = self.genesis_hash
             block_time = int(time.time()) + 1
         else:
@@ -100,7 +100,7 @@
         height = self.block_heights[base_block_hash] + 1
         coinbase = create_coinbase(height)
         coinbase.rehash()
-        if spend == None:
+        if spend is None:
             # We need to have something to spend to fill the block.
             assert_equal(block_size, 0)
             block = create_block(base_block_hash, coinbase, block_time)
@@ -133,7 +133,7 @@
             base_tx_size = len(tx.serialize()) + 18
 
             # If a specific script is required, add it.
-            if script != None:
+            if script is not None:
                 tx.vout.append(CTxOut(1, script))
 
             # Put some random data into the first transaction of the chain to randomize ids.
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
@@ -77,7 +77,7 @@
         return tx
 
     def next_block(self, number, spend=None, script=CScript([OP_TRUE]), block_size=0):
-        if self.tip == None:
+        if self.tip is None:
             base_block_hash = self.genesis_hash
             block_time = int(time.time()) + 1
         else:
@@ -87,7 +87,7 @@
         height = self.block_heights[base_block_hash] + 1
         coinbase = create_coinbase(height)
         coinbase.rehash()
-        if spend == None:
+        if spend is None:
             # We need to have something to spend to fill the block.
             assert_equal(block_size, 0)
             block = create_block(base_block_hash, coinbase, block_time)
@@ -120,7 +120,7 @@
             base_tx_size = len(tx.serialize()) + 18
 
             # If a specific script is required, add it.
-            if script != None:
+            if script is not None:
                 tx.vout.append(CTxOut(1, script))
 
             # Put some random data into the first transaction of the chain to randomize ids.
diff --git a/test/functional/abc-replay-protection.py b/test/functional/abc-replay-protection.py
--- a/test/functional/abc-replay-protection.py
+++ b/test/functional/abc-replay-protection.py
@@ -64,7 +64,7 @@
                             "-replayprotectionactivationtime={}".format(REPLAY_PROTECTION_START_TIME)]]
 
     def next_block(self, number):
-        if self.tip == None:
+        if self.tip is None:
             base_block_hash = self.genesis_hash
             block_time = int(time.time()) + 1
         else:
diff --git a/test/functional/abc-segwit-recovery.py b/test/functional/abc-segwit-recovery.py
--- a/test/functional/abc-segwit-recovery.py
+++ b/test/functional/abc-segwit-recovery.py
@@ -83,7 +83,7 @@
                            ["-acceptnonstdtxn=0"]]
 
     def next_block(self, number):
-        if self.tip == None:
+        if self.tip is None:
             base_block_hash = self.genesis_hash
             block_time = TEST_TIME
         else:
diff --git a/test/functional/abc-transaction-ordering.py b/test/functional/abc-transaction-ordering.py
--- a/test/functional/abc-transaction-ordering.py
+++ b/test/functional/abc-transaction-ordering.py
@@ -54,7 +54,7 @@
         block.vtx.extend(tx_list)
 
     def next_block(self, number, spend=None, tx_count=0):
-        if self.tip == None:
+        if self.tip is None:
             base_block_hash = self.genesis_hash
             block_time = int(time.time()) + 1
         else:
@@ -64,7 +64,7 @@
         height = self.block_heights[base_block_hash] + 1
         coinbase = create_coinbase(height)
         coinbase.rehash()
-        if spend == None:
+        if spend is None:
             # We need to have something to spend to fill the block.
             block = create_block(base_block_hash, coinbase, block_time)
         else:
diff --git a/test/functional/interface_http.py b/test/functional/interface_http.py
--- a/test/functional/interface_http.py
+++ b/test/functional/interface_http.py
@@ -33,7 +33,7 @@
         conn.request('POST', '/', '{"method": "getbestblockhash"}', headers)
         out1 = conn.getresponse().read()
         assert b'"error":null' in out1
-        assert conn.sock != None
+        assert conn.sock is not None
         # according to http/1.1 connection must still be open!
 
         # send 2nd request without closing connection
@@ -41,7 +41,7 @@
         out1 = conn.getresponse().read()
         assert b'"error":null' in out1
         # must also response with a correct json-rpc message
-        assert conn.sock != None
+        assert conn.sock is not None
         # according to http/1.1 connection must still be open!
         conn.close()
 
@@ -55,7 +55,7 @@
         conn.request('POST', '/', '{"method": "getbestblockhash"}', headers)
         out1 = conn.getresponse().read()
         assert b'"error":null' in out1
-        assert conn.sock != None
+        assert conn.sock is not None
         # according to http/1.1 connection must still be open!
 
         # send 2nd request without closing connection
@@ -63,7 +63,7 @@
         out1 = conn.getresponse().read()
         assert b'"error":null' in out1
         # must also response with a correct json-rpc message
-        assert conn.sock != None
+        assert conn.sock is not None
         # according to http/1.1 connection must still be open!
         conn.close()
 
@@ -76,7 +76,7 @@
         conn.request('POST', '/', '{"method": "getbestblockhash"}', headers)
         out1 = conn.getresponse().read()
         assert b'"error":null' in out1
-        assert conn.sock == None
+        assert conn.sock is None
         # now the connection must be closed after the response
 
         # node1 (2nd node) is running with disabled keep-alive option
@@ -101,7 +101,7 @@
         conn.request('POST', '/', '{"method": "getbestblockhash"}', headers)
         out1 = conn.getresponse().read()
         assert b'"error":null' in out1
-        assert conn.sock != None
+        assert conn.sock is not None
         # connection must be closed because bitcoind should use
         # keep-alive by default
 
diff --git a/test/functional/mining_prioritisetransaction.py b/test/functional/mining_prioritisetransaction.py
--- a/test/functional/mining_prioritisetransaction.py
+++ b/test/functional/mining_prioritisetransaction.py
@@ -70,7 +70,7 @@
         high_fee_tx = confirmed_transactions[1]
 
         # Something high-fee should have been mined!
-        assert high_fee_tx != None
+        assert high_fee_tx is not None
 
         # Add a prioritisation before a tx is in the mempool (de-prioritising a
         # high-fee transaction so that it's now low fee).
diff --git a/test/functional/test_framework/blocktools.py b/test/functional/test_framework/blocktools.py
--- a/test/functional/test_framework/blocktools.py
+++ b/test/functional/test_framework/blocktools.py
@@ -80,7 +80,7 @@
     coinbaseoutput.nValue = 50 * COIN
     halvings = int(height / 150)  # regtest
     coinbaseoutput.nValue >>= halvings
-    if (pubkey != None):
+    if (pubkey is not None):
         coinbaseoutput.scriptPubKey = CScript([pubkey, OP_CHECKSIG])
     else:
         coinbaseoutput.scriptPubKey = CScript([OP_TRUE])
diff --git a/test/functional/test_framework/messages.py b/test/functional/test_framework/messages.py
--- a/test/functional/test_framework/messages.py
+++ b/test/functional/test_framework/messages.py
@@ -647,7 +647,7 @@
         self.shortids = []
         self.prefilled_txn = []
 
-        if p2pheaders_and_shortids != None:
+        if p2pheaders_and_shortids is not None:
             self.header = p2pheaders_and_shortids.header
             self.nonce = p2pheaders_and_shortids.nonce
             self.shortids = p2pheaders_and_shortids.shortids
@@ -704,7 +704,7 @@
 
     def __init__(self, blockhash=0, indexes=None):
         self.blockhash = blockhash
-        self.indexes = indexes if indexes != None else []
+        self.indexes = indexes if indexes is not None else []
 
     def deserialize(self, f):
         self.blockhash = deser_uint256(f)
@@ -746,7 +746,7 @@
 
     def __init__(self, blockhash=0, transactions=None):
         self.blockhash = blockhash
-        self.transactions = transactions if transactions != None else []
+        self.transactions = transactions if transactions is not None else []
 
     def deserialize(self, f):
         self.blockhash = deser_uint256(f)
@@ -936,7 +936,7 @@
     command = b"getdata"
 
     def __init__(self, inv=None):
-        self.inv = inv if inv != None else []
+        self.inv = inv if inv is not None else []
 
     def deserialize(self, f):
         self.inv = deser_vector(f, CInv)
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
@@ -174,7 +174,7 @@
 
         while True:
             msg = self._on_data()
-            if msg == None:
+            if msg is None:
                 break
             self.on_message(msg)
 
diff --git a/test/functional/test_framework/test_node.py b/test/functional/test_framework/test_node.py
--- a/test/functional/test_framework/test_node.py
+++ b/test/functional/test_framework/test_node.py
@@ -70,7 +70,7 @@
             raise FileNotFoundError(
                 "Binary '{}' could not be found.\nTry setting it manually:\n\tBITCOIND=<path/to/bitcoind> {}".format(self.binary, sys.argv[0]))
         self.coverage_dir = coverage_dir
-        if extra_conf != None:
+        if extra_conf is not None:
             append_config(datadir, extra_conf)
         # Most callers will just need to add extra args to the default list
         # below.
diff --git a/test/functional/test_framework/util.py b/test/functional/test_framework/util.py
--- a/test/functional/test_framework/util.py
+++ b/test/functional/test_framework/util.py
@@ -317,7 +317,7 @@
 
 def rpc_url(datadir, host, port):
     rpc_u, rpc_p = get_auth_cookie(datadir)
-    if host == None:
+    if host is None:
         host = '127.0.0.1'
     return "http://{}:{}@{}:{}".format(rpc_u, rpc_p, host, int(port))
 
@@ -407,7 +407,7 @@
 
 def connect_nodes(from_node, to_node):
     host = to_node.host
-    if host == None:
+    if host is None:
         host = '127.0.0.1'
     ip_port = host + ':' + str(to_node.p2p_port)
     from_node.addnode(ip_port, "onetry")
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
@@ -132,7 +132,7 @@
 
 
 def on_ci():
-    return os.getenv('TRAVIS') == 'true' or os.getenv('TEAMCITY_VERSION') != None
+    return os.getenv('TRAVIS') == 'true' or os.getenv('TEAMCITY_VERSION') is not None
 
 
 def main():