tests: Handle ImportError explicitly, improve comparisons against None

contrib/devtools/clang-format-diff.py

@@ -109,7 +109,7 @@ def main():
     match = re.search('^\+\+\+\ (.*?/){%s}(\S*)' % args.p, line)
     if match:
       filename = match.group(2)
-    if filename == None:
+    if filename is None:
       continue
 
     if args.regex is not None:

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/github-merge.py

@@ -25,7 +25,7 @@
 import codecs
 try:
     from urllib.request import Request,urlopen
-except:
+except ImportError:
     from urllib2 import Request,urlopen
 
 # External tools (can be overridden using environment)

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 @@ def run_test(self):
         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 @@ def run_test(self):
         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 @@ def run_test(self):
         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 @@ def run_test(self):
         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 @@ def run_test(self):
                 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 @@ def __init__(self, p2pheaders_and_shortids = None):
         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 @@ def __init__(self, i, datadir, *, rpchost, timewait, bitcoind, bitcoin_cli, mock
         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.

test/lint/lint-python.sh

@@ -36,6 +36,7 @@ export LC_ALL=C
 # E701 multiple statements on one line (colon)
 # E702 multiple statements on one line (semicolon)
 # E703 statement ends with a semicolon
+# E711 comparison to None should be 'if cond is None:'
 # E714 test for object identity should be "is not"
 # E721 do not compare types, use "isinstance()"
 # E741 do not use variables named "l", "O", or "I"
@@ -87,4 +88,4 @@ elif PYTHONWARNINGS="ignore" flake8 --version | grep -q "Python 2"; then
     exit 0
 fi
 
-PYTHONWARNINGS="ignore" flake8 --ignore=B,C,E,F,I,N,W --select=E101,E112,E113,E115,E116,E125,E129,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,W191,W291,W292,W293,W504,W601,W602,W603,W604,W605,W606 "${@:-.}"
+PYTHONWARNINGS="ignore" flake8 --ignore=B,C,E,F,I,N,W --select=E101,E112,E113,E115,E116,E125,E129,E131,E133,E223,E224,E242,E266,E271,E272,E273,E274,E275,E304,E306,E401,E402,E502,E701,E702,E703,E711,E714,E721,E741,E742,E743,E901,E902,F401,F402,F403,F404,F405,F406,F407,F601,F602,F621,F622,F631,F701,F702,F703,F704,F705,F706,F707,F811,F812,F821,F822,F823,F831,F841,W191,W291,W292,W293,W504,W601,W602,W603,W604,W605,W606 "${@:-.}"