fix fail_if_no_c

Author: blink1073

tools/fail_if_no_c.py

@@ -29,13 +29,19 @@
 import bson  # noqa: E402
 import pymongo  # noqa: E402
 
-if not pymongo.has_c() or not bson.has_c():
-    try:
-        from pymongo import _cmessage  # type:ignore[attr-defined] # noqa: F401
-    except Exception as e:
-        LOGGER.exception(e)
-    try:
-        from bson import _cbson  # type:ignore[attr-defined] # noqa: F401
-    except Exception as e:
-        LOGGER.exception(e)
-    sys.exit("could not load C extensions")
+
+def main():
+    if not pymongo.has_c() or not bson.has_c():
+        try:
+            from pymongo import _cmessage  # type:ignore[attr-defined] # noqa: F401
+        except Exception as e:
+            LOGGER.exception(e)
+        try:
+            from bson import _cbson  # type:ignore[attr-defined] # noqa: F401
+        except Exception as e:
+            LOGGER.exception(e)
+        sys.exit("could not load C extensions")
+
+
+if __name__ == "__main__":
+    main()