Use walrus operator

Author: Cito

webware/MiscUtils/M2PickleRPC.py

@@ -34,21 +34,15 @@ def make_connection(self, host, port=None):
     def parse_response(self, f):
         """Workaround M2Crypto issue mentioned above."""
         sio = BytesIO()
-        while True:
-            chunk = f.read()
-            if not chunk:
-                break
+        while chunk := f.read():
             sio.write(chunk)
         sio.seek(0)
         return Transport.parse_response(self, sio)
 
     def parse_response_gzip(self, f):
         """Workaround M2Crypto issue mentioned above."""
         sio = BytesIO()
-        while True:
-            chunk = f.read()
-            if not chunk:
-                break
+        while chunk := f.read():
             sio.write(chunk)
         sio.seek(0)
         return Transport.parse_response_gzip(self, sio)

webware/MiscUtils/MixIn.py

@@ -66,8 +66,7 @@ def foo(self):
 
         # Track the mix-ins made for a particular class
         attrName = 'mixInsFor' + pyClass.__name__
-        mixIns = getattr(pyClass, attrName, None)
-        if mixIns is None:
+        if (mixIns := getattr(pyClass, attrName, None)) is None:
             mixIns = []
             setattr(pyClass, attrName, mixIns)
 

webware/MiscUtils/NamedValueAccess.py

@@ -75,14 +75,10 @@ def valueForKey(obj, key, default=NoDefault):
             method = getattr(cls, key, None)
         if not method:
             underKey = '_' + key
-            method = getattr(cls, underKey, None) if cls else None
-            if not method:
-                attr = getattr(obj, key, NoDefault)
-                if attr is NoDefault:
-                    attr = getattr(obj, underKey, NoDefault)
-                    if attr is NoDefault and cls is not None:
-                        getitem = getattr(cls, '__getitem__', None)
-                        if getitem:
+            if not (method := getattr(cls, underKey, None) if cls else None):
+                if (attr := getattr(obj, key, NoDefault)) is NoDefault:
+                    if (attr := getattr(obj, underKey, NoDefault)) is NoDefault and cls is not None:
+                        if getitem := getattr(cls, '__getitem__', None):
                             try:
                                 getitem(obj, key)
                             except KeyError:

webware/PSP/BraceConverter.py

@@ -82,8 +82,7 @@ def parseLine(self, line, writer):
 
     def openBlock(self, writer):
         """Open a new block."""
-        match = self._reColonBrace.match(self.line)
-        if match and not self.dictLevel:
+        if (match := self._reColonBrace.match(self.line)) and not self.dictLevel:
             writer.printChars(':')
             writer.pushIndent()
             if match.group(1):

webware/Tests/TestEndToEnd/TestServer.py

@@ -120,8 +120,7 @@ def run(self):
                    encoding='utf-8', stdout=PIPE, stderr=STDOUT) as p:
             outputStarted = False
             while True:
-                ret = p.poll()
-                if ret is not None:
+                if (ret := p.poll()) is not None:
                     break
                 line = p.stdout.readline().rstrip()
                 if line:
@@ -133,8 +132,7 @@ def run(self):
             self.pollQueue.put(ret)
             if ret is None:
                 while True:
-                    ret = p.poll()
-                    if ret is not None:
+                    if (ret := p.poll()) is not None:
                         break
                     line = p.stdout.readline().rstrip()
                     self.outputQueue.put(line)

webware/Transaction.py

@@ -197,8 +197,7 @@ def writeExceptionReport(self, handler):
         handler.writeAttrs(self, self._exceptionReportAttrNames)
 
         for name in self._exceptionReportAttrNames:
-            obj = getattr(self, '_' + name, None)
-            if obj:
+            if obj := getattr(self, '_' + name, None):
                 try:
                     obj.writeExceptionReport(handler)
                 except Exception:

webware/URLParser.py

@@ -266,8 +266,7 @@ def parse(self, trans, requestPath):
             context.append('')
         parts = []
         while context:
-            contextName = '/'.join(context)
-            if contextName in self._contexts:
+            if (contextName := '/'.join(context)) in self._contexts:
                 break
             parts.insert(0, context.pop())
         if context:
@@ -645,7 +644,7 @@ def parseInit(self, trans, requestPath):
                 redirectTo = mod.urlRedirect['']
             else:
                 redirectTo = None
-            if redirectTo:
+            if redirectTo := (mod.urlRedirect.get(nextPart) or mod.urlRedirect.get('')):
                 if isinstance(redirectTo, str):
                     fp = FileParser(os.path.join(self._path, redirectTo))
                 else:

webware/UnknownFileTypeServlet.py

@@ -78,8 +78,7 @@ def filename(self, trans):
         A subclass could override this in order to serve files from other
         disk locations based on some logic.
         """
-        filename = getattr(self, '_serverSideFilename', None)
-        if filename is None:
+        if (filename := getattr(self, '_serverSideFilename', None)) is None:
             filename = trans.request().serverSidePath()
             self._serverSideFilename = filename  # cache it
         return filename
@@ -199,8 +198,7 @@ def serveContent(self, trans):
                 print('>> UnknownFileType.serveContent()')
                 print('>> filename =', filename)
                 print('>> size=', fileSize)
-            fileDict = fileCache.get(filename)
-            if fileDict is not None and mtime != fileDict['mtime']:
+            if (fileDict := fileCache.get(filename)) is not None and mtime != fileDict['mtime']:
                 # Cache is out of date; clear it.
                 if debug:
                     print('>> changed, clearing cache')
@@ -241,8 +239,7 @@ def serveContent(self, trans):
                     print('>> sending directly')
                 numBytesSent = 0
                 while numBytesSent < fileSize:
-                    data = f.read(min(fileSize-numBytesSent, readBufferSize))
-                    if data == '':
+                    if not (data := f.read(min(fileSize-numBytesSent, readBufferSize))):
                         break  # unlikely, but safety first
                     response.write(data)
                     numBytesSent += len(data)