Windows: avoid unecessary class attributes

BoboTiG · BoboTiG · commit 2c53af926dfb · 2018-12-26T22:22:23.000+01:00
diff --git a/CHANGELOG b/CHANGELOG
@@ -5,6 +5,7 @@ History:
 4.0.0   201x/xx/xx
       - MSS: renamed MSSBase to MSSMixin in base.py
       - Linux: ensure resources are freed in grab()
+      - Windows: avoid unecessary class attributes
       - MSS: fix Flake8 C408: Unnecessary dict call - rewrite as a literal, in exceptions.py
       - MSS: fix Flake8 I100: Import statements are in the wrong order
       - MSS: fix Flake8 I201: Missing newline before sections or imports
diff --git a/mss/windows.py b/mss/windows.py
@@ -52,18 +52,15 @@ class BITMAPINFO(ctypes.Structure):
 class MSS(MSSMixin):
     """ Multiple ScreenShots implementation for Microsoft Windows. """
 
-    _bbox = {"height": 0, "width": 0}
-    _bmp = None
-    _data = None
-    _memdc = None
-    _srcdc = None
-
     def __init__(self):
         # type: () -> None
         """ Windows initialisations. """
 
         self._monitors = []  # type: List[Dict[str, int]]
 
+        self._bbox = {"height": 0, "width": 0}
+        self._bmp = None
+
         self.monitorenumproc = ctypes.WINFUNCTYPE(
             ctypes.wintypes.INT,
             ctypes.wintypes.DWORD,
@@ -100,7 +97,8 @@ def __exit__(self, *args):
         # type: (*str) -> None
         """ Cleanup. """
 
-        for attr in (self._bmp, self._memdc, self._srcdc):
+        for attribute in {"_bmp", "_memdc", "_srcdc"}:
+            attr = getattr(self, attribute, None)
             if attr:
                 ctypes.windll.gdi32.DeleteObject(attr)
 
