Fix invalid string comparisons

Identity checks should never be used with strings, it may fail based on
Python's interning logic.

12 files changed, 24 insertions, 21 deletions

diff --git a/ant_landscape/__init__.py b/ant_landscape/__init__.py
index 68dd2342..8fbfb79d 100644
--- a/ant_landscape/__init__.py
+++ b/ant_landscape/__init__.py
@@ -391,7 +391,7 @@ class AntDisplaceSettingsPanel(bpy.types.Panel):
         if not ant.sphere_mesh:
             col = box.column()
             col.prop(ant, "edge_falloff")
-            if ant.edge_falloff is not "0":
+            if ant.edge_falloff != "0":
                 col = box.column(align=True)
                 col.prop(ant, "edge_level")
                 if ant.edge_falloff in ["2", "3"]:
@@ -401,7 +401,7 @@ class AntDisplaceSettingsPanel(bpy.types.Panel):
 
         col = box.column()
         col.prop(ant, "strata_type")
-        if ant.strata_type is not "0":
+        if ant.strata_type != "0":
             col = box.column()
             col.prop(ant, "strata")
         col = box.column()
diff --git a/ant_landscape/ant_functions.py b/ant_landscape/ant_functions.py
index 3c0f2c34..bee655c0 100644
--- a/ant_landscape/ant_functions.py
+++ b/ant_landscape/ant_functions.py
@@ -662,7 +662,7 @@ def draw_ant_displace(self, context, generate=True):
             if not self.sphere_mesh:
                 col = box.column()
                 col.prop(self, "edge_falloff")
-                if self.edge_falloff is not "0":
+                if self.edge_falloff != "0":
                     col = box.column(align=True)
                     col.prop(self, "edge_level")
                     if self.edge_falloff in ["2", "3"]:
@@ -672,7 +672,7 @@ def draw_ant_displace(self, context, generate=True):
 
         col = box.column()
         col.prop(self, "strata_type")
-        if self.strata_type is not "0":
+        if self.strata_type != "0":
             col = box.column()
             col.prop(self, "strata")
 
diff --git a/archipack/archipack_fence.py b/archipack/archipack_fence.py
index a94023fd..c2989be2 100644
--- a/archipack/archipack_fence.py
+++ b/archipack/archipack_fence.py
@@ -1489,7 +1489,7 @@ class ARCHIPACK_PT_fence(Panel):
         row = box.row(align=True)
         row.operator("archipack.fence_curve_update", text="", icon='FILE_REFRESH')
         row.prop_search(prop, "user_defined_path", scene, "objects", text="", icon='OUTLINER_OB_CURVE')
-        if prop.user_defined_path is not "":
+        if prop.user_defined_path != "":
             box.prop(prop, 'user_defined_spline')
             box.prop(prop, 'user_defined_resolution')
         box.prop(prop, 'angle_limit')
diff --git a/archipack/archipack_stair.py b/archipack/archipack_stair.py
index 94a8da7c..6e3d6212 100644
--- a/archipack/archipack_stair.py
+++ b/archipack/archipack_stair.py
@@ -2518,7 +2518,7 @@ class archipack_stair(ArchipackObject, Manipulable, PropertyGroup):
 
         self.setup_manipulators()
 
-        if self.presets is not 'STAIR_O':
+        if self.presets != 'STAIR_O':
             for i, part in enumerate(self.parts):
                 if i >= self.n_parts:
                     break
diff --git a/development_iskeyfree.py b/development_iskeyfree.py
index 7851afee..332e11d4 100644
--- a/development_iskeyfree.py
+++ b/development_iskeyfree.py
@@ -105,18 +105,18 @@ class MyChecker():
         cls.mylist.clear()
         for e in sortkeys:
             cmd = ""
-            if e[2] is not "":
+            if e[2] != "":
                 cmd += e[2] + "+"
-            if e[3] is not "":
+            if e[3] != "":
                 cmd += e[3] + "+"
-            if e[4] is not "":
+            if e[4] != "":
                 cmd += e[4] + "+"
-            if e[5] is not "":
+            if e[5] != "":
                 cmd += e[5] + "+"
 
             cmd += e[1]
 
-            if e[6] is not "":
+            if e[6] != "":
                 cmd += "  " + e[6]
             cls.mylist.append([e[0], cmd])
 
diff --git a/io_import_images_as_planes.py b/io_import_images_as_planes.py
index 1f32bc5f..a4aa98f2 100644
--- a/io_import_images_as_planes.py
+++ b/io_import_images_as_planes.py
@@ -1094,7 +1094,7 @@ class IMPORT_IMAGE_OT_to_plane(Operator, AddObjectHelper):
         bpy.ops.mesh.primitive_plane_add('INVOKE_REGION_WIN')
         plane = context.scene.objects.active
         # Why does mesh.primitive_plane_add leave the object in edit mode???
-        if plane.mode is not 'OBJECT':
+        if plane.mode != 'OBJECT':
             bpy.ops.object.mode_set(mode='OBJECT')
         plane.dimensions = width, height, 0.0
         plane.data.name = plane.name = name
diff --git a/io_scene_fbx/import_fbx.py b/io_scene_fbx/import_fbx.py
index 90dc08df..addb8ae6 100644
--- a/io_scene_fbx/import_fbx.py
+++ b/io_scene_fbx/import_fbx.py
@@ -1126,7 +1126,7 @@ def blen_read_geom_layer_normal(fbx_obj, mesh, xform=None):
         bdata = [None] * len(blen_data) if is_fake else blen_data
         if func(mesh, bdata, "normal",
                 fbx_layer_data, fbx_layer_index, fbx_layer_mapping, fbx_layer_ref, 3, 3, layer_id, xform, True):
-            if blen_data_type is "Polygons":
+            if blen_data_type == "Polygons":
                 for pidx, p in enumerate(mesh.polygons):
                     for lidx in range(p.loop_start, p.loop_start + p.loop_total):
                         mesh.loops[lidx].normal[:] = bdata[pidx]
diff --git a/measureit/measureit_geometry.py b/measureit/measureit_geometry.py
index 3b2e0186..e0b036d6 100644
--- a/measureit/measureit_geometry.py
+++ b/measureit/measureit_geometry.py
@@ -831,9 +831,9 @@ def draw_text(myobj, pos2d, display_text, rgb, fsize, align='L', text_rot=0.0):
     # -------------------
     for line in mylines:
         text_width, text_height = blf.dimensions(font_id, line)
-        if align is 'C':
+        if align == 'C':
             newx = x_pos - text_width / 2
-        elif align is 'R':
+        elif align == 'R':
             newx = x_pos - text_width - gap
         else:
             newx = x_pos
@@ -851,7 +851,7 @@ def draw_text(myobj, pos2d, display_text, rgb, fsize, align='L', text_rot=0.0):
         if maxwidth < text_width:
             maxwidth = text_width
 
-    if align is 'L':
+    if align == 'L':
         blf.disable(font_id, ROTATION)
 
     return maxwidth, maxheight
diff --git a/mesh_bsurfaces.py b/mesh_bsurfaces.py
index ffe16e04..53b88d49 100644
--- a/mesh_bsurfaces.py
+++ b/mesh_bsurfaces.py
@@ -2928,7 +2928,7 @@ class GPENCIL_OT_SURFSK_add_surface(Operator):
                 for i in range(0, len(surface_splines_parsed[0])):
                     surface_splines_parsed[0][i] = self.main_object.matrix_world * verts_ordered_V2[i].co
 
-        # When "Automatic join" option is active (and the selection type is not "TWO_CONNECTED"),
+        # When "Automatic join" option is active (and the selection type != "TWO_CONNECTED"),
         # merge the verts of the tips of the loops when they are "near enough"
         if self.automatic_join and selection_type != "TWO_CONNECTED":
             # Join the tips of "Follow" loops that are near enough and must be "closed"
diff --git a/mesh_extra_tools/mesh_extrude_and_reshape.py b/mesh_extra_tools/mesh_extrude_and_reshape.py
index 8716bfb1..f4eef683 100644
--- a/mesh_extra_tools/mesh_extrude_and_reshape.py
+++ b/mesh_extra_tools/mesh_extrude_and_reshape.py
@@ -245,7 +245,7 @@ class Extrude_and_Reshape(Operator):
 
     @classmethod
     def poll(cls, context):
-        return context.mode is not 'EDIT_MESH'
+        return context.mode != 'EDIT_MESH'
 
     def modal(self, context, event):
         if self.confirm:
diff --git a/node_wrangler.py b/node_wrangler.py
index 6ccf2ecd..b535a580 100644
--- a/node_wrangler.py
+++ b/node_wrangler.py
@@ -2358,7 +2358,10 @@ class NWCopySettings(Operator, NWBase):
     def poll(cls, context):
         valid = False
         if nw_check(context):
-            if context.active_node is not None and context.active_node.type is not 'FRAME':
+            if (
+                    context.active_node is not None and
+                    context.active_node.type != 'FRAME'
+            ):
                 valid = True
         return valid
 
@@ -2941,7 +2944,7 @@ class NWAddReroutes(Operator, NWBase):
             reroutes_count = 0  # will be used when aligning reroutes added to hidden nodes
             for out_i, output in enumerate(node.outputs):
                 pass_used = False  # initial value to be analyzed if 'R_LAYERS'
-                # if node is not 'R_LAYERS' - "pass_used" not needed, so set it to True
+                # if node != 'R_LAYERS' - "pass_used" not needed, so set it to True
                 if node.type != 'R_LAYERS':
                     pass_used = True
                 else:  # if 'R_LAYERS' check if output represent used render pass
diff --git a/space_view3d_pie_menus/pie_save_open_menu.py b/space_view3d_pie_menus/pie_save_open_menu.py
index bdd9b63c..3d48e591 100644
--- a/space_view3d_pie_menus/pie_save_open_menu.py
+++ b/space_view3d_pie_menus/pie_save_open_menu.py
@@ -130,7 +130,7 @@ class FileIncrementalSave(Operator):
 
     @classmethod
     def poll(cls, context):
-        return (bpy.data.filepath is not "")
+        return (bpy.data.filepath != "")
 
     def execute(self, context):
         f_path = bpy.data.filepath