chore:try4 fixing flake8 errors

src/meanvariancefunction.py

@@ -26,9 +26,8 @@ def mean_variance(filepath: str, output_dir: str = os.getcwd()+'/') -> str:
         ValueError: If there are no files in directory
 
     """
-
-    # Open each file in the input directory, raises error if no file is found
     files = [file for file in glob(filepath)]
+    # Open each file in the input directory, raises error if no file is found
 
     if len(files) == 0:
         raise ValueError('No files in directory:', filepath)