diff --git a/.arclint b/.arclint
--- a/.arclint
+++ b/.arclint
@@ -21,7 +21,7 @@
             "type": "flake8",
             "include": "(\\.py$)",
             "flags": [
-                "--select=E112,E113,E115,E116,E125,E131,E133,E223,E224,E271,E272,E273,E274,E275,E304,E306,E502,E702,E703,E714,E721,E741,E742,E743,F401,F402,F403,F404,F405,F406,F407,F601,F602,F621,F622,F631,F701,F702,F703,F704,F705,F706,F707,F811,F812,F822,F823,F831,W292,W601,W602,W603,W604,W605"
+                "--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,W292,W293,W601,W602,W603,W604,W605,W606"
             ]
         },
         "lint-format-strings": {
diff --git a/contrib/linearize/linearize-data.py b/contrib/linearize/linearize-data.py
--- a/contrib/linearize/linearize-data.py
+++ b/contrib/linearize/linearize-data.py
@@ -21,8 +21,6 @@
 
 settings = {}
 
-##### Switch endian-ness #####
-
 
 def hex_switchEndian(s):
     """ Switches the endianness of a hex string (in pairs of hex chars) """
diff --git a/contrib/linearize/linearize-hashes.py b/contrib/linearize/linearize-hashes.py
--- a/contrib/linearize/linearize-hashes.py
+++ b/contrib/linearize/linearize-hashes.py
@@ -21,8 +21,6 @@
 
 settings = {}
 
-##### Switch endian-ness #####
-
 
 def hex_switchEndian(s):
     """ Switches the endianness of a hex string (in pairs of hex chars) """
diff --git a/contrib/seeds/generate-seeds.py b/contrib/seeds/generate-seeds.py
--- a/contrib/seeds/generate-seeds.py
+++ b/contrib/seeds/generate-seeds.py
@@ -48,7 +48,7 @@
     if len(addr) > 6 and addr.endswith('.onion'):
         vchAddr = b32decode(addr[0:-6], True)
         if len(vchAddr) != 16 - len(pchOnionCat):
-            raise ValueError('Invalid onion {}'.format(s))
+            raise ValueError('Invalid onion {}'.format(vchAddr))
         return pchOnionCat + vchAddr
     elif '.' in addr:  # IPv4
         return pchIPv4 + bytearray((int(x) for x in addr.split('.')))
diff --git a/contrib/seeds/makeseeds.py b/contrib/seeds/makeseeds.py
--- a/contrib/seeds/makeseeds.py
+++ b/contrib/seeds/makeseeds.py
@@ -8,8 +8,9 @@
 
 import collections
 import dns.resolver
-import sys
 import re
+import sys
+
 NSEEDS = 512
 
 MAX_SEEDS_PER_ASN = 2
diff --git a/test/functional/abc-finalize-block.py b/test/functional/abc-finalize-block.py
--- a/test/functional/abc-finalize-block.py
+++ b/test/functional/abc-finalize-block.py
@@ -226,7 +226,7 @@
         assert_equal(node.getbestblockhash(), alt_node_new_tip)
         assert_equal(node.getfinalizedblockhash(), fork_block)
 
-        ### TEST FINALIZATION DELAY ###
+        # TEST FINALIZATION DELAY
 
         self.log.info("Check that finalization delay prevents eclipse attacks")
         # Because there has been no delay since the beginning of this test,
diff --git a/test/functional/interface_rest.py b/test/functional/interface_rest.py
--- a/test/functional/interface_rest.py
+++ b/test/functional/interface_rest.py
@@ -202,11 +202,11 @@
                                req_type=ReqType.JSON, status=400, ret_type=RetType.OBJ)
 
         # Test limits
-        long_uri = '/'.join(["{}-{}".format(txid, n) for n in range(20)])
+        long_uri = '/'.join(["{}-{}".format(txid, n_) for n_ in range(20)])
         self.test_rest_request("/getutxos/checkmempool/{}".format(long_uri),
                                http_method='POST', status=400, ret_type=RetType.OBJ)
 
-        long_uri = '/'.join(['{}-{}'.format(txid, n) for n in range(15)])
+        long_uri = '/'.join(['{}-{}'.format(txid, n_) for n_ in range(15)])
         self.test_rest_request(
             "/getutxos/checkmempool/{}".format(long_uri), http_method='POST', status=200)
 
diff --git a/test/functional/p2p_leak.py b/test/functional/p2p_leak.py
--- a/test/functional/p2p_leak.py
+++ b/test/functional/p2p_leak.py
@@ -13,6 +13,11 @@
 
 import time
 
+from test_framework.messages import (
+    msg_getaddr,
+    msg_ping,
+    msg_verack,
+)
 from test_framework.mininode import (
     mininode_lock,
     network_thread_join,