#2503 make singletons compared with "is" not == or !=

Thanks to Wummel for the patch


git-svn-id: http://svn.python.org/projects/python/trunk@62043 6015fed2-1504-0410-9fe1-9d1591cc4771

Author: benjamin.peterson

Demo/classes/Dbm.py

@@ -50,7 +50,7 @@ def test():
                 value = d[key]
                 print 'currently:', value
             value = input('value: ')
-            if value == None:
+            if value is None:
                 del d[key]
             else:
                 d[key] = value

Demo/curses/ncurses.py

@@ -9,7 +9,7 @@
 from curses import panel
 
 def wGetchar(win = None):
-    if win == None: win = stdscr
+    if win is None: win = stdscr
     return win.getch()
 
 def Getchar():

Demo/rpc/mountclient.py

@@ -100,7 +100,7 @@ def bindsocket(self):
     # This function is called to cough up a suitable
     # authentication object for a call to procedure 'proc'.
     def mkcred(self):
-        if self.cred == None:
+        if self.cred is None:
             self.cred = rpc.AUTH_UNIX, rpc.make_auth_unix_default()
         return self.cred
 

Demo/rpc/nfsclient.py

@@ -129,7 +129,7 @@ def addpackers(self):
         self.unpacker = NFSUnpacker('')
 
     def mkcred(self):
-        if self.cred == None:
+        if self.cred is None:
             self.cred = rpc.AUTH_UNIX, rpc.make_auth_unix_default()
         return self.cred
 
@@ -170,7 +170,7 @@ def Listdir(self, dir):
             for fileid, name, cookie in entries:
                 list.append((fileid, name))
                 last_cookie = cookie
-            if eof or last_cookie == None:
+            if eof or last_cookie is None:
                 break
             ra = (ra[0], last_cookie, ra[2])
         return list
@@ -184,7 +184,7 @@ def test():
     else: filesys = None
     from mountclient import UDPMountClient, TCPMountClient
     mcl = TCPMountClient(host)
-    if filesys == None:
+    if filesys is None:
         list = mcl.Export()
         for item in list:
             print item

Demo/rpc/rpc.py

@@ -264,13 +264,13 @@ def do_call(self):
 
     def mkcred(self):
         # Override this to use more powerful credentials
-        if self.cred == None:
+        if self.cred is None:
             self.cred = (AUTH_NULL, make_auth_null())
         return self.cred
 
     def mkverf(self):
         # Override this to use a more powerful verifier
-        if self.verf == None:
+        if self.verf is None:
             self.verf = (AUTH_NULL, make_auth_null())
         return self.verf
 
@@ -321,7 +321,7 @@ def recvrecord(sock):
 def bindresvport(sock, host):
     global last_resv_port_tried
     FIRST, LAST = 600, 1024 # Range of ports to try
-    if last_resv_port_tried == None:
+    if last_resv_port_tried is None:
         import os
         last_resv_port_tried = FIRST + os.getpid() % (LAST-FIRST)
     for i in range(last_resv_port_tried, LAST) + \
@@ -814,7 +814,7 @@ def loop(self):
     def session(self):
         call, host_port = self.sock.recvfrom(8192)
         reply = self.handle(call)
-        if reply != None:
+        if reply is not None:
             self.sock.sendto(reply, host_port)
 
 

Demo/tkinter/guido/paint.py

@@ -50,7 +50,7 @@ def b1up(event):
 def motion(event):
     if b1 == "down":
         global xold, yold
-        if xold != None and yold != None:
+        if xold is not None and yold is not None:
             event.widget.create_line(xold,yold,event.x,event.y,smooth=TRUE)
                           # here's where you draw it. smooth. neat.
         xold = event.x

Lib/bsddb/dbshelve.py

@@ -133,7 +133,7 @@ def __delitem__(self, key):
 
 
     def keys(self, txn=None):
-        if txn != None:
+        if txn is not None:
             return self.db.keys(txn)
         else:
             return self.db.keys()
@@ -157,7 +157,7 @@ def __repr__(self):
 
 
     def items(self, txn=None):
-        if txn != None:
+        if txn is not None:
             items = self.db.items(txn)
         else:
             items = self.db.items()
@@ -168,7 +168,7 @@ def items(self, txn=None):
         return newitems
 
     def values(self, txn=None):
-        if txn != None:
+        if txn is not None:
             values = self.db.values(txn)
         else:
             values = self.db.values()

Lib/bsddb/test/test_basics.py

@@ -363,7 +363,7 @@ def test03_SimpleCursorStuff(self, get_raises_error=0, set_raises_error=0):
         else:
             if set_raises_error:
                 self.fail("expected exception")
-            if n != None:
+            if n is not None:
                 self.fail("expected None: %r" % (n,))
 
         rec = c.get_both('0404', self.makeData('0404'))
@@ -377,7 +377,7 @@ def test03_SimpleCursorStuff(self, get_raises_error=0, set_raises_error=0):
         else:
             if get_raises_error:
                 self.fail("expected exception")
-            if n != None:
+            if n is not None:
                 self.fail("expected None: %r" % (n,))
 
         if self.d.get_type() == db.DB_BTREE:

Lib/bsddb/test/test_dbtables.py

@@ -323,7 +323,7 @@ def test_Modify(self):
         self.tdb.Insert(tabname, {'Type': 'Unknown', 'Access': '0'})
 
         def set_type(type):
-            if type == None:
+            if type is None:
                 return 'MP3'
             return type
 

Lib/idlelib/AutoComplete.py

@@ -35,10 +35,9 @@ class AutoComplete:
                                    "popupwait", type="int", default=0)
 
     def __init__(self, editwin=None):
-        if editwin == None:  # subprocess and test
-            self.editwin = None
-            return
         self.editwin = editwin
+        if editwin is None:  # subprocess and test
+            return
         self.text = editwin.text
         self.autocompletewindow = None
 

Lib/idlelib/PyShell.py

@@ -932,7 +932,7 @@ def close(self):
                 "The program is still running!\n Do you want to kill it?",
                 default="ok",
                 parent=self.text)
-            if response == False:
+            if response is False:
                 return "cancel"
         if self.reading:
             self.top.quit()

Lib/lib-tk/Tkinter.py

@@ -188,7 +188,7 @@ def __init__(self, master=None, value=None, name=None):
         else:
             self._name = 'PY_VAR' + repr(_varnum)
             _varnum += 1
-        if value != None:
+        if value is not None:
             self.set(value)
         elif not self._tk.call("info", "exists", self._name):
             self.set(self._default)

Lib/lib-tk/turtle.py

@@ -749,25 +749,25 @@ def setup(**geometry):
     global _width, _height, _startx, _starty
 
     width = geometry.get('width',_width)
-    if width >= 0 or width == None:
+    if width >= 0 or width is None:
         _width = width
     else:
         raise ValueError, "width can not be less than 0"
 
     height = geometry.get('height',_height)
-    if height >= 0 or height == None:
+    if height >= 0 or height is None:
         _height = height
     else:
         raise ValueError, "height can not be less than 0"
 
     startx = geometry.get('startx', _startx)
-    if startx >= 0 or startx == None:
+    if startx >= 0 or startx is None:
         _startx = _startx
     else:
         raise ValueError, "startx can not be less than 0"
 
     starty = geometry.get('starty', _starty)
-    if starty >= 0 or starty == None:
+    if starty >= 0 or starty is None:
         _starty = starty
     else:
         raise ValueError, "startx can not be less than 0"

Lib/plat-mac/EasyDialogs.py

@@ -79,7 +79,7 @@ def Message(msg, id=260, ok=None):
         return
     h = d.GetDialogItemAsControl(2)
     SetDialogItemText(h, lf2cr(msg))
-    if ok != None:
+    if ok is not None:
         h = d.GetDialogItemAsControl(1)
         h.SetControlTitle(ok)
     d.SetDialogDefaultItem(1)
@@ -116,10 +116,10 @@ def AskString(prompt, default = "", id=261, ok=None, cancel=None):
     SetDialogItemText(h, lf2cr(default))
     d.SelectDialogItemText(4, 0, 999)
 #       d.SetDialogItem(4, 0, 255)
-    if ok != None:
+    if ok is not None:
         h = d.GetDialogItemAsControl(1)
         h.SetControlTitle(ok)
-    if cancel != None:
+    if cancel is not None:
         h = d.GetDialogItemAsControl(2)
         h.SetControlTitle(cancel)
     d.SetDialogDefaultItem(1)
@@ -160,10 +160,10 @@ def AskPassword(prompt,  default='', id=264, ok=None, cancel=None):
     SetControlData(pwd, kControlEditTextPart, kControlEditTextPasswordTag, default)
     d.SelectDialogItemText(4, 0, 999)
     Ctl.SetKeyboardFocus(d.GetDialogWindow(), pwd, kControlEditTextPart)
-    if ok != None:
+    if ok is not None:
         h = d.GetDialogItemAsControl(1)
         h.SetControlTitle(ok)
-    if cancel != None:
+    if cancel is not None:
         h = d.GetDialogItemAsControl(2)
         h.SetControlTitle(cancel)
     d.SetDialogDefaultItem(Dialogs.ok)
@@ -204,19 +204,19 @@ def AskYesNoCancel(question, default = 0, yes=None, no=None, cancel=None, id=262
     # The question string is item 5
     h = d.GetDialogItemAsControl(5)
     SetDialogItemText(h, lf2cr(question))
-    if yes != None:
+    if yes is not None:
         if yes == '':
             d.HideDialogItem(2)
         else:
             h = d.GetDialogItemAsControl(2)
             h.SetControlTitle(yes)
-    if no != None:
+    if no is not None:
         if no == '':
             d.HideDialogItem(3)
         else:
             h = d.GetDialogItemAsControl(3)
             h.SetControlTitle(no)
-    if cancel != None:
+    if cancel is not None:
         if cancel == '':
             d.HideDialogItem(4)
         else:
@@ -317,7 +317,7 @@ def _update(self, value):
 
     def set(self, value, max=None):
         """set(value) - Set progress bar position"""
-        if max != None:
+        if max is not None:
             self.maxval = max
             bar = self.d.GetDialogItemAsControl(3)
             if max <= 0:    # indeterminate bar

Lib/plat-mac/FrameWork.py

@@ -92,7 +92,7 @@ def windowbounds(width, height):
 def setwatchcursor():
     global _watch
 
-    if _watch == None:
+    if _watch is None:
         _watch = GetCursor(4).data
     SetCursor(_watch)
 
@@ -129,7 +129,7 @@ def makeusermenus(self):
         self._quititem = MenuItem(m, "Quit", "Q", self._quit)
 
     def gethelpmenu(self):
-        if self._helpmenu == None:
+        if self._helpmenu is None:
             self._helpmenu = HelpMenu(self.menubar)
         return self._helpmenu
 
@@ -266,7 +266,7 @@ def do_mouseDown(self, event):
         else:
             name = "do_%d" % partcode
 
-        if wid == None:
+        if wid is None:
             # No window, or a non-python window
             try:
                 handler = getattr(self, name)
@@ -475,7 +475,7 @@ def close(self):
         self.menus = None
 
     def addmenu(self, title, after = 0, id=None):
-        if id == None:
+        if id is None:
             id = self.getnextid()
         if DEBUG: print 'Newmenu', title, id # XXXX
         m = NewMenu(id, title)
@@ -907,8 +907,8 @@ def scrollbars(self, wantx=1, wanty=1):
         self.barx_enabled = self.bary_enabled = 1
         x0, y0, x1, y1 = self.wid.GetWindowPort().GetPortBounds()
         vx, vy = self.getscrollbarvalues()
-        if vx == None: self.barx_enabled, vx = 0, 0
-        if vy == None: self.bary_enabled, vy = 0, 0
+        if vx is None: self.barx_enabled, vx = 0, 0
+        if vy is None: self.bary_enabled, vy = 0, 0
         if wantx:
             rect = x0-1, y1-(SCROLLBARWIDTH-1), x1-(SCROLLBARWIDTH-2), y1+1
             self.barx = NewControl(self.wid, rect, "", 1, vx, 0, 32767, 16, 0)
@@ -1007,7 +1007,7 @@ def updatescrollbars(self):
         SetPort(self.wid)
         vx, vy = self.getscrollbarvalues()
         if self.barx:
-            if vx == None:
+            if vx is None:
                 self.barx.HiliteControl(255)
                 self.barx_enabled = 0
             else:
@@ -1017,7 +1017,7 @@ def updatescrollbars(self):
                         self.barx.HiliteControl(0)
                 self.barx.SetControlValue(vx)
         if self.bary:
-            if vy == None:
+            if vy is None:
                 self.bary.HiliteControl(255)
                 self.bary_enabled = 0
             else:

Lib/plat-mac/MiniAEFrame.py

@@ -158,7 +158,7 @@ def callback_wrapper(self, _request, _reply):
             #Same try/except comment as above
             rv = _function(**_parameters)
 
-        if rv == None:
+        if rv is None:
             aetools.packevent(_reply, {})
         else:
             aetools.packevent(_reply, {'----':rv})

Lib/plat-mac/PixMapWrapper.py

@@ -146,9 +146,9 @@ def blit(self, x1=0,y1=0,x2=None,y2=None, port=None):
         """Draw this pixmap into the given (default current) grafport."""
         src = self.bounds
         dest = [x1,y1,x2,y2]
-        if x2 == None:
+        if x2 is None:
             dest[2] = x1 + src[2]-src[0]
-        if y2 == None:
+        if y2 is None:
             dest[3] = y1 + src[3]-src[1]
         if not port: port = Qd.GetPort()
         Qd.CopyBits(self.PixMap(), port.GetPortBitMapForCopyBits(), src, tuple(dest),

Lib/plat-mac/aepack.py

@@ -77,7 +77,7 @@ def pack(x, forcetype = None):
         else:
             return pack(x).AECoerceDesc(forcetype)
 
-    if x == None:
+    if x is None:
         return AE.AECreateDesc('null', '')
 
     if isinstance(x, AEDescType):

Lib/plat-mac/buildtools.py

@@ -203,13 +203,13 @@ def process_common(template, progress, code, rsrcname, destname, is_update,
     dummy, tmplowner = copyres(input, output, skiptypes, 1, progress)
 
     Res.CloseResFile(input)
-##  if ownertype == None:
+##  if ownertype is None:
 ##      raise BuildError, "No owner resource found in either resource file or template"
     # Make sure we're manipulating the output resource file now
 
     Res.UseResFile(output)
 
-    if ownertype == None:
+    if ownertype is None:
         # No owner resource in the template. We have skipped the
         # Python owner resource, so we have to add our own. The relevant
         # bundle stuff is already included in the interpret/applet template.