Code modernization. Replace v=s[i]; del s[i] with single lookup v=s.pop(i)

Lib/Queue.py

@@ -146,6 +146,4 @@ class Queue:
 
     # Get an item from the queue
     def _get(self):
-        item = self.queue[0]
+        return self.queue.pop(0)
-        del self.queue[0]
-        return item

Lib/asynchat.py

@@ -269,9 +269,7 @@ class fifo:
 
     def pop (self):
         if self.list:
-            result = self.list[0]
+            return (1, self.list.pop(0))
-            del self.list[0]
-            return (1, result)
         else:
             return (0, None)
 

Lib/cgi.py

@@ -323,8 +323,7 @@ def parse_header(line):
 
     """
     plist = map(lambda x: x.strip(), line.split(';'))
-    key = plist[0].lower()
+    key = plist.pop(0).lower()
-    del plist[0]
     pdict = {}
     for p in plist:
         i = p.find('=')

Lib/cmd.py

@@ -109,8 +109,7 @@ class Cmd:
         stop = None
         while not stop:
             if self.cmdqueue:
-                line = self.cmdqueue[0]
+                line = self.cmdqueue.pop(0)
-                del self.cmdqueue[0]
             else:
                 if self.use_rawinput:
                     try:
@@ -261,11 +260,10 @@ class Cmd:
         names = []
         classes = [self.__class__]
         while classes:
-            aclass = classes[0]
+            aclass = classes.pop(0)
             if aclass.__bases__:
                 classes = classes + list(aclass.__bases__)
             names = names + dir(aclass)
-            del classes[0]
         return names
 
     def complete_help(self, *args):

Lib/imaplib.py

@@ -973,11 +973,10 @@ class IMAP4:
             return typ, dat
         if not name in self.untagged_responses:
             return typ, [None]
-        data = self.untagged_responses[name]
+        data = self.untagged_responses.pop(name)
         if __debug__:
             if self.debug >= 5:
                 self._mesg('untagged_responses[%s] => %s' % (name, data))
-        del self.untagged_responses[name]
         return typ, data
 
 

Lib/mailbox.py

@@ -202,8 +202,7 @@ class MHMailbox:
     def next(self):
         if not self.boxes:
             return None
-        fn = self.boxes[0]
+        fn = self.boxes.pop(0)
-        del self.boxes[0]
         fp = open(os.path.join(self.dirname, fn))
         return self.factory(fp)
 
@@ -233,8 +232,7 @@ class Maildir:
     def next(self):
         if not self.boxes:
             return None
-        fn = self.boxes[0]
+        fn = self.boxes.pop(0)
-        del self.boxes[0]
         fp = open(fn)
         return self.factory(fp)
 

Lib/multifile.py

@@ -160,8 +160,7 @@ class MultiFile:
         self.level = max(0, self.level - 1)
         del self.stack[0]
         if self.seekable:
-            self.start = self.posstack[0]
+            self.start = self.posstack.pop(0)
-            del self.posstack[0]
             if self.level > 0:
                 self.lastpos = abslastpos - self.start
 

Lib/mutex.py

@@ -44,8 +44,7 @@ class mutex:
         """Unlock a mutex.  If the queue is not empty, call the next
         function with its argument."""
         if self.queue:
-            function, argument = self.queue[0]
+            function, argument = self.queue.pop(0)
-            del self.queue[0]
             function(argument)
         else:
             self.locked = 0

Lib/pickle.py

@@ -692,11 +692,7 @@ class Unpickler:
     dispatch[PERSID] = load_persid
 
     def load_binpersid(self):
-        stack = self.stack
+        pid = self.stack.pop()
-
-        pid = stack[-1]
-        del stack[-1]
-
         self.append(self.persistent_load(pid))
     dispatch[BINPERSID] = load_binpersid
 
@@ -977,8 +973,7 @@ class Unpickler:
 
     def load_append(self):
         stack = self.stack
-        value = stack[-1]
+        value = stack.pop()
-        del stack[-1]
         list = stack[-1]
         list.append(value)
     dispatch[APPEND] = load_append
@@ -995,9 +990,8 @@ class Unpickler:
 
     def load_setitem(self):
         stack = self.stack
-        value = stack[-1]
+        value = stack.pop()
-        key = stack[-2]
+        key = stack.pop()
-        del stack[-2:]
         dict = stack[-1]
         dict[key] = value
     dispatch[SETITEM] = load_setitem
@@ -1014,8 +1008,7 @@ class Unpickler:
 
     def load_build(self):
         stack = self.stack
-        value = stack[-1]
+        value = stack.pop()
-        del stack[-1]
         inst = stack[-1]
         try:
             setstate = inst.__setstate__
@@ -1038,8 +1031,7 @@ class Unpickler:
     dispatch[MARK] = load_mark
 
     def load_stop(self):
-        value = self.stack[-1]
+        value = self.stack.pop()
-        del self.stack[-1]
         raise _Stop(value)
     dispatch[STOP] = load_stop
 

Lib/threading.py

@@ -633,8 +633,7 @@ def _test():
             while not self.queue:
                 self._note("get(): queue empty")
                 self.rc.wait()
-            item = self.queue[0]
+            item = self.queue.pop(0)
-            del self.queue[0]
             self._note("get(): got %s, %d left", item, len(self.queue))
             self.wc.notify()
             self.mon.release()

Lib/xmlrpclib.py

@@ -779,16 +779,14 @@ class Unmarshaller:
     dispatch["name"] = end_string # struct keys are always strings
 
     def end_array(self, data):
-        mark = self._marks[-1]
+        mark = self._marks.pop()
-        del self._marks[-1]
         # map arrays to Python lists
         self._stack[mark:] = [self._stack[mark:]]
         self._value = 0
     dispatch["array"] = end_array
 
     def end_struct(self, data):
-        mark = self._marks[-1]
+        mark = self._marks.pop()
-        del self._marks[-1]
         # map structs to Python dictionaries
         dict = {}
         items = self._stack[mark:]