Use "not in"

src/PIL/GdImageFile.py

@@ -47,7 +47,7 @@ def _open(self):
         # Header
         s = self.fp.read(1037)
 
-        if not i16(s) in [65534, 65535]:
+        if i16(s) not in [65534, 65535]:
             msg = "Not a valid GD 2.x .gd file"
             raise SyntaxError(msg)
 

src/PIL/Image.py

@@ -1731,7 +1731,7 @@ def alpha_composite(self, im, dest=(0, 0), source=(0, 0)):
         if not isinstance(dest, (list, tuple)):
             msg = "Destination must be a tuple"
             raise ValueError(msg)
-        if not len(source) in (2, 4):
+        if len(source) not in (2, 4):
             msg = "Source must be a 2 or 4-tuple"
             raise ValueError(msg)
         if not len(dest) == 2:

src/PIL/features.py

@@ -24,7 +24,7 @@ def check_module(feature):
     :returns: ``True`` if available, ``False`` otherwise.
     :raises ValueError: If the module is not defined in this version of Pillow.
     """
-    if not (feature in modules):
+    if feature not in modules:
         msg = f"Unknown module {feature}"
         raise ValueError(msg)