Compare to None with is/is not

contrib/devtools/copyright_header.py

@@ -491,7 +491,7 @@ def get_git_change_year_range(filename):
 
 def file_already_has_core_copyright(file_lines):
     index, _ = get_updatable_copyright_line(file_lines)
-    return index != None
+    return index is not None
 
 ################################################################################
 # insert header execution

contrib/devtools/update-translations.py

@@ -125,7 +125,7 @@ def escape_cdata(text):
     return text
 
 def contains_bitcoin_addr(text, errors):
-    if text != None and ADDRESS_REGEXP.search(text) != None:
+    if text is not None and ADDRESS_REGEXP.search(text) is not None:
         errors.append('Translation "%s" contains a bitcoin address. This will be removed.' % (text))
         return True
     return False

test/functional/interface_http.py

@@ -31,13 +31,13 @@ class HTTPBasicsTest (BitcoinTestFramework):
         conn.request('POST', '/', '{"method": "getbestblockhash"}', headers)
         out1 = conn.getresponse().read()
         assert(b'"error":null' in out1)
-        assert(conn.sock!=None) #according to http/1.1 connection must still be open!
+        assert(conn.sock is not None) #according to http/1.1 connection must still be open!
 
         #send 2nd request without closing connection
         conn.request('POST', '/', '{"method": "getchaintips"}', headers)
         out1 = conn.getresponse().read()
         assert(b'"error":null' in out1) #must also response with a correct json-rpc message
-        assert(conn.sock!=None) #according to http/1.1 connection must still be open!
+        assert(conn.sock is not None) #according to http/1.1 connection must still be open!
         conn.close()
 
         #same should be if we add keep-alive because this should be the std. behaviour
@@ -48,13 +48,13 @@ class HTTPBasicsTest (BitcoinTestFramework):
         conn.request('POST', '/', '{"method": "getbestblockhash"}', headers)
         out1 = conn.getresponse().read()
         assert(b'"error":null' in out1)
-        assert(conn.sock!=None) #according to http/1.1 connection must still be open!
+        assert(conn.sock is not None) #according to http/1.1 connection must still be open!
 
         #send 2nd request without closing connection
         conn.request('POST', '/', '{"method": "getchaintips"}', headers)
         out1 = conn.getresponse().read()
         assert(b'"error":null' in out1) #must also response with a correct json-rpc message
-        assert(conn.sock!=None) #according to http/1.1 connection must still be open!
+        assert(conn.sock is not None) #according to http/1.1 connection must still be open!
         conn.close()
 
         #now do the same with "Connection: close"
@@ -65,7 +65,7 @@ class HTTPBasicsTest (BitcoinTestFramework):
         conn.request('POST', '/', '{"method": "getbestblockhash"}', headers)
         out1 = conn.getresponse().read()
         assert(b'"error":null' in out1)
-        assert(conn.sock==None) #now the connection must be closed after the response
+        assert(conn.sock is None) #now the connection must be closed after the response
 
         #node1 (2nd node) is running with disabled keep-alive option
         urlNode1 = urllib.parse.urlparse(self.nodes[1].url)
@@ -88,7 +88,7 @@ class HTTPBasicsTest (BitcoinTestFramework):
         conn.request('POST', '/', '{"method": "getbestblockhash"}', headers)
         out1 = conn.getresponse().read()
         assert(b'"error":null' in out1)
-        assert(conn.sock!=None) #connection must be closed because bitcoind should use keep-alive by default
+        assert(conn.sock is not None) #connection must be closed because bitcoind should use keep-alive by default
 
         # Check excessive request size
         conn = http.client.HTTPConnection(urlNode2.hostname, urlNode2.port)

test/functional/mining_prioritisetransaction.py

@@ -84,7 +84,7 @@ class PrioritiseTransactionTest(BitcoinTestFramework):
                 high_fee_tx = x
 
         # 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).

test/functional/test_framework/messages.py

@@ -764,7 +764,7 @@ class HeaderAndShortIDs:
         self.prefilled_txn = []
         self.use_witness = False
 
-        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
@@ -822,7 +822,7 @@ class BlockTransactionsRequest:
 
     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)
@@ -863,7 +863,7 @@ class BlockTransactions:
 
     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)
@@ -1052,7 +1052,7 @@ class msg_getdata:
     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)

test/functional/test_framework/test_node.py

@@ -68,7 +68,7 @@ class TestNode():
         self.rpc_timeout = timewait
         self.binary = bitcoind
         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 standard list below.
         # For those callers that need more flexibility, they can just set the args property directly.