diff --git a/.arclint b/.arclint
--- a/.arclint
+++ b/.arclint
@@ -26,7 +26,7 @@
             "include": "(\\.py$)",
             "flags": [
                 "--select=E,W,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",
-                "--ignore=E501,E704,E713,E722,E731,W503,W504"
+                "--ignore=E501,E704,E722,E731,W503,W504"
             ]
         },
         "lint-format-strings": {
diff --git a/contrib/devtools/symbol-check.py b/contrib/devtools/symbol-check.py
--- a/contrib/devtools/symbol-check.py
+++ b/contrib/devtools/symbol-check.py
@@ -139,7 +139,7 @@
         lib = version
         ver = '0'
     ver = tuple([int(x) for x in ver.split('.')])
-    if not lib in max_versions:
+    if lib not in max_versions:
         return False
     return ver <= max_versions[lib] or lib == 'GLIBC' and ver <= ARCH_MIN_GLIBC_VER[arch]
 
diff --git a/contrib/gitian-build.py b/contrib/gitian-build.py
--- a/contrib/gitian-build.py
+++ b/contrib/gitian-build.py
@@ -254,9 +254,9 @@
         os.environ['USE_DOCKER'] = '1'
     elif not args.kvm:
         os.environ['USE_LXC'] = '1'
-        if not 'GITIAN_HOST_IP' in os.environ.keys():
+        if 'GITIAN_HOST_IP' not in os.environ.keys():
             os.environ['GITIAN_HOST_IP'] = '10.0.3.1'
-        if not 'LXC_GUEST_IP' in os.environ.keys():
+        if 'LXC_GUEST_IP' not in os.environ.keys():
             os.environ['LXC_GUEST_IP'] = '10.0.3.5'
 
     # Disable for MacOS if no SDK found
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
@@ -240,7 +240,7 @@
                 self.inFn, self.inF.tell(), inhdr, blk_hdr, inLen)
 
             self.hash_str = calc_hash_str(blk_hdr)
-            if not self.hash_str in blkmap:
+            if self.hash_str not in blkmap:
                 # Because blocks can be written to files out-of-order as of 0.10, the script
                 # may encounter blocks it doesn't know about. Treat as debug output.
                 if settings['debug_output'] == 'true':
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
@@ -226,7 +226,7 @@
 
     # Check all tests with parameters actually exist
     for test in TEST_PARAMS:
-        if not test in all_scripts:
+        if test not in all_scripts:
             print("ERROR: Test with parameter {} does not exist, check it has "
                   "not been renamed or deleted".format(test))
             sys.exit(1)
diff --git a/test/functional/wallet_abandonconflict.py b/test/functional/wallet_abandonconflict.py
--- a/test/functional/wallet_abandonconflict.py
+++ b/test/functional/wallet_abandonconflict.py
@@ -137,7 +137,7 @@
         assert_equal(unconfbalance, newbalance)
         # Unconfirmed transactions which are not in the mempool should also
         # not be in listunspent
-        assert not txABC2 in [utxo["txid"]
+        assert txABC2 not in [utxo["txid"]
                               for utxo in self.nodes[0].listunspent(0)]
         balance = newbalance