diff --git a/tests/test_commandline.py b/tests/test_commandline.py
index 9f6163ac..0feb1d95 100644
--- a/tests/test_commandline.py
+++ b/tests/test_commandline.py
@@ -60,10 +60,12 @@
 # Filename for the black/white list of options
 FILENAME_OPTIONLIST = "tests/option_list.tsv"
 
+
 class DummyError(Exception):
     """Custom exception for controlling test flow."""
     pass
 
+
 def filter_files(files):
     '''Filter list of files according to filters set in the configuration file tests/_test_commandline.yml'''
     testing_dir = TestUtils.get_tests_directory()
@@ -84,6 +86,7 @@ def filter_files(files):
                     files = list(filter(rx.search, files))
     return files
 
+
 def LocalStart(parser, *args, **kwargs):
     '''Stub for E.start - captures the parser for inspection.'''
     global PARSER
@@ -91,6 +94,7 @@ def LocalStart(parser, *args, **kwargs):
     PARSER = ORIGINAL_START(parser, **kwargs)
     raise DummyError()
 
+
 def load_script(script_name):
     '''Attempts to import a script as a module for inspection.'''
     script_path = os.path.splitext(script_name)[0]
@@ -110,6 +114,7 @@ def load_script(script_name):
 
     return module, module_name
 
+
 def test_cmdline():
     '''Test command line interfaces of scripts for style and conformity.'''
     global ORIGINAL_START
@@ -167,6 +172,7 @@ def test_cmdline():
         if module_name in sys.modules:
             del sys.modules[module_name]
 
+
 def check_option(option, script_name, option_actions):
     print(f"Checking option: {option} in script: {script_name}")  # Diagnostic print
     assert option in option_actions, f"Option {option} in script {script_name} is unknown or not allowed."