use with statement to ensure zipfile is always closed (closes #20102)

Lib/shutil.py

@@ -680,17 +680,15 @@ def _make_zipfile(base_name, base_dir, verbose=0, dry_run=0, logger=None):
                         zip_filename, base_dir)
 
         if not dry_run:
-            zip = zipfile.ZipFile(zip_filename, "w",
-                                  compression=zipfile.ZIP_DEFLATED)
-
-            for dirpath, dirnames, filenames in os.walk(base_dir):
-                for name in filenames:
-                    path = os.path.normpath(os.path.join(dirpath, name))
-                    if os.path.isfile(path):
-                        zip.write(path, path)
-                        if logger is not None:
-                            logger.info("adding '%s'", path)
-            zip.close()
+            with zipfile.ZipFile(zip_filename, "w",
+                                 compression=zipfile.ZIP_DEFLATED) as zf:
+                for dirpath, dirnames, filenames in os.walk(base_dir):
+                    for name in filenames:
+                        path = os.path.normpath(os.path.join(dirpath, name))
+                        if os.path.isfile(path):
+                            zf.write(path, path)
+                            if logger is not None:
+                                logger.info("adding '%s'", path)
 
     return zip_filename