python: avoid equality check for None

PEP8 says that:
"Comparisons to singletons like None should always be done with is or
is not, never the equality operators."

glib uses a mix of "== None" and "is None". This patch changes all
cases to the latter.

gio/gdbus-2.0/codegen/codegen.py

@@ -1068,7 +1068,7 @@ class CodeGenerator:
                            '\n')
 
     def generate_annotations(self, prefix, annotations):
-        if annotations == None:
+        if annotations is None:
             return
 
         n = 0

gio/gdbus-2.0/codegen/codegen_main.py

@@ -63,38 +63,38 @@ def apply_annotation(iface_list, iface, method, signal, prop, arg, key, value):
             iface_obj = i
             break
 
-    if iface_obj == None:
+    if iface_obj is None:
         print_error('No interface "{}"'.format(iface))
 
     target_obj = None
 
     if method:
         method_obj = find_method(iface_obj, method)
-        if method_obj == None:
+        if method_obj is None:
             print_error('No method "{}" on interface "{}"'.format(method, iface))
         if arg:
             arg_obj = find_arg(method_obj.in_args, arg)
-            if (arg_obj == None):
+            if (arg_obj is None):
                 arg_obj = find_arg(method_obj.out_args, arg)
-                if (arg_obj == None):
+                if (arg_obj is None):
                     print_error('No arg "{}" on method "{}" on interface "{}"'.format(arg, method, iface))
             target_obj = arg_obj
         else:
             target_obj = method_obj
     elif signal:
         signal_obj = find_signal(iface_obj, signal)
-        if signal_obj == None:
+        if signal_obj is None:
             print_error('No signal "{}" on interface "{}"'.format(signal, iface))
         if arg:
             arg_obj = find_arg(signal_obj.args, arg)
-            if (arg_obj == None):
+            if (arg_obj is None):
                 print_error('No arg "{}" on signal "{}" on interface "{}"'.format(arg, signal, iface))
             target_obj = arg_obj
         else:
             target_obj = signal_obj
     elif prop:
         prop_obj = find_prop(iface_obj, prop)
-        if prop_obj == None:
+        if prop_obj is None:
             print_error('No property "{}" on interface "{}"'.format(prop, iface))
         target_obj = prop_obj
     else:

gio/gdbus-2.0/codegen/dbustypes.py

@@ -61,7 +61,7 @@ class Arg:
         if len(self.since) == 0:
             self.since = utils.lookup_since(self.annotations)
 
-        if self.name == None:
+        if self.name is None:
             self.name = 'unnamed_arg%d'%arg_number
         # default to GVariant
         self.ctype_in_g  = 'GVariant *'

gio/gdbus-2.0/codegen/utils.py

@@ -116,21 +116,21 @@ def lookup_annotation(annotations, key):
 
 def lookup_docs(annotations):
     s = lookup_annotation(annotations, 'org.gtk.GDBus.DocString')
-    if s == None:
+    if s is None:
         return ''
     else:
         return s
 
 def lookup_since(annotations):
     s = lookup_annotation(annotations, 'org.gtk.GDBus.Since')
-    if s == None:
+    if s is None:
         return ''
     else:
         return s
 
 def lookup_brief_docs(annotations):
     s = lookup_annotation(annotations, 'org.gtk.GDBus.DocString.Short')
-    if s == None:
+    if s is None:
         return ''
     else:
         return s

glib/glib_gdb.py

@@ -9,7 +9,7 @@ def read_global_var (symname):
     return gdb.selected_frame().read_var(symname)
 
 def g_quark_to_string (quark):
-    if quark == None:
+    if quark is None:
         return None
     quark = long(quark)
     if quark == 0:
@@ -171,7 +171,7 @@ def pretty_printer_lookup (val):
     return None
 
 def register (obj):
-    if obj == None:
+    if obj is None:
         obj = gdb
 
     obj.pretty_printers.append(pretty_printer_lookup)

glib/update-gtranslit.py

@@ -104,7 +104,7 @@ class Mapping:
         return [self]
 
     def serialise(self, serialiser):
-        if self.serialised == None:
+        if self.serialised is None:
             self.serialised = serialiser.add_mapping(self.mapping)
 
         return self.serialised
@@ -193,7 +193,7 @@ class Chain:
             return [self]
 
     def serialise(self, serialiser):
-        if self.serialised == None:
+        if self.serialised is None:
             # Before we serialise, see if we can optimise a bit
             self.chain = sum((item.get_flattened() for item in self.chain), [])
 

gobject/gobject_gdb.py

@@ -26,7 +26,7 @@ def g_type_to_typenode (gtype):
         if typenode == 0:
             return None
         val = read_global_var ("static_fundamental_type_nodes")
-        if val == None:
+        if val is None:
             return None
         return val[typenode >> 2].address
 
@@ -132,7 +132,7 @@ def pretty_printer_lookup (val):
     return None
 
 def get_signal_name (id):
-    if id == None:
+    if id is None:
         return None
     id = long(id)
     if id == 0:
@@ -163,7 +163,7 @@ class SignalFrame(FrameDecorator):
     def read_var (self, frame, name, array = None):
         try:
             v = frame_var (frame, name)
-            if v == None or v.is_optimized_out:
+            if v is None or v.is_optimized_out:
                 return None
             if array != None:
                 array.append (v)
@@ -174,7 +174,7 @@ class SignalFrame(FrameDecorator):
     def read_object (self, frame, name, array = None):
         try:
             v = frame_var (frame, name)
-            if v == None or v.is_optimized_out:
+            if v is None or v.is_optimized_out:
                 return None
             v = v.cast (gdb.lookup_type("GObject").pointer())
             # Ensure this is a somewhat correct object pointer
@@ -323,7 +323,7 @@ class GFrameFilter(object):
         return GFrameDecorator(iterator)
 
 def register (obj):
-    if obj == None:
+    if obj is None:
         obj = gdb
 
     if HAVE_GDB_FRAMEDECORATOR: