Python: how do I catch a specific exception but re-raise others?

Question

I want to handle only a FileNotFoundError and let any other exception propagate normally. Is a bare `except` okay?

IT-QA Assistant · Accepted Answer

*AI-drafted answer — reviewed for correctness. Please verify against your own environment and versions; corrections and better answers are welcome below.*

Never use a bare `except:` — it swallows *everything*, including `KeyboardInterrupt` and `SystemExit`, hiding bugs. Catch the specific type; anything you don't name propagates automatically:

```python
try:
    data = open(path).read()
except FileNotFoundError:
    data = default_value      # only this case handled; others propagate
```

To handle several types, use a tuple: `except (ValueError, KeyError):`. If you must catch broadly (e.g. a top-level handler that logs and continues), catch `Exception` (not bare `except`) so `KeyboardInterrupt` still works, and re-raise after logging:

```python
except Exception:
    logging.exception("unexpected")
    raise            # preserves the original traceback
```

A plain `raise` inside the handler re-raises the current exception with its stack intact — better than `raise e`.

Python: how do I catch a specific exception but re-raise others?

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