diff --git a/httprunner/exceptions.py b/httprunner/exceptions.py
index 787e864d..403c5ff8 100644
--- a/httprunner/exceptions.py
+++ b/httprunner/exceptions.py
@@ -6,18 +6,23 @@ from httprunner.compat import JSONDecodeError, FileNotFoundError
     these exceptions will mark test as failure
 """
 
+
 class MyBaseFailure(Exception):
     pass
 
+
 class ValidationFailure(MyBaseFailure):
     pass
 
+
 class ExtractFailure(MyBaseFailure):
     pass
 
+
 class SetupHooksFailure(MyBaseFailure):
     pass
 
+
 class TeardownHooksFailure(MyBaseFailure):
     pass
 
@@ -26,35 +31,46 @@ class TeardownHooksFailure(MyBaseFailure):
     these exceptions will mark test as error
 """
 
+
 class MyBaseError(Exception):
     pass
 
+
 class FileFormatError(MyBaseError):
     pass
 
+
 class ParamsError(MyBaseError):
     pass
 
+
 class NotFoundError(MyBaseError):
     pass
 
+
 class FileNotFound(FileNotFoundError, NotFoundError):
     pass
 
+
 class FunctionNotFound(NotFoundError):
     pass
 
+
 class VariableNotFound(NotFoundError):
     pass
 
+
 class EnvNotFound(NotFoundError):
     pass
 
+
 class CSVNotFound(NotFoundError):
     pass
 
+
 class ApiNotFound(NotFoundError):
     pass
 
+
 class TestcaseNotFound(NotFoundError):
     pass