Unused exception object¶
ID: py/unused-exception-object
Kind: problem
Security severity:
Severity: error
Precision: very-high
Tags:
- quality
- reliability
- error-handling
Query suites:
- python-security-and-quality.qls
Click to see the query in the CodeQL repository
Creating a new exception object is no different from creating any other object. The exception needs to be raised to have an effect.
Recommendation¶
Insert a raise before the exception.
Example¶
In this example, the first function do_action_forgotten_raise() silently ignores any erroneous input. Whereas, the second function do_action correctly raises an exception if the ‘action’ is not understood.
def do_action_forgotten_raise(action):
if action == "go":
start()
elif action == "stop":
stop()
else:
ValueError(action)
def do_action(action):
if action == "go":
start()
elif action == "stop":
stop()
else:
raise ValueError(action)