diff --git a/boxes/__init__.py b/boxes/__init__.py
index baeda35..f5b2e15 100755
--- a/boxes/__init__.py
+++ b/boxes/__init__.py
@@ -706,7 +706,7 @@ class Boxes:
 
         Flush canvas to disk and convert output to requested format if needed.
         Call after .render()"""
-        if self.ctx == None:
+        if self.ctx is None:
             return
 
         self.ctx.stroke()
diff --git a/boxes/generators/atreus21.py b/boxes/generators/atreus21.py
index 386cb50..14f1c64 100644
--- a/boxes/generators/atreus21.py
+++ b/boxes/generators/atreus21.py
@@ -87,7 +87,7 @@ class Atreus21(Boxes, Keyboard):
 
     @restore
     def half(self, hole_cb=None, reverse=False):
-        if hole_cb == None:
+        if hole_cb is None:
             hole_cb = self.key
         self.moveTo(self.half_btn, self.half_btn)
         self.apply_callback_on_columns(
diff --git a/boxes/generators/dividertray.py b/boxes/generators/dividertray.py
index 49f9c56..36e36c2 100644
--- a/boxes/generators/dividertray.py
+++ b/boxes/generators/dividertray.py
@@ -449,8 +449,8 @@ class SlotDescription:
     ):
         self.depth = depth
         self.width = width
-        self.start_radius = radius if start_radius == None else start_radius
-        self.end_radius = radius if end_radius == None else end_radius
+        self.start_radius = radius if start_radius is None else start_radius
+        self.end_radius = radius if end_radius is None else end_radius
         self.angle = angle
 
     def __repr__(self):
diff --git a/boxes/generators/keyboard.py b/boxes/generators/keyboard.py
index 353cb3d..9c2bc3e 100644
--- a/boxes/generators/keyboard.py
+++ b/boxes/generators/keyboard.py
@@ -165,7 +165,7 @@ class Keyboard:
             grid_hole(3, -4, led_hole_size)
 
     def apply_callback_on_columns(self, cb, columns_definition, spacing=None, reverse=False):
-        if spacing == None:
+        if spacing is None:
             spacing = self.STANDARD_KEY_SPACING
         if reverse:
             columns_definition = list(reversed(columns_definition))