Python try/except Patterns

Error Handling

try/except/else/finally

Structure your exception handling using all four clauses for clarity.

See templateLog errors properly

Template

try:
    payload = parse(raw)
except json.JSONDecodeError as exc:
    logger.error("Invalid JSON: %s", exc)
    raise
else:
    process(payload)
finally:
    clean_up()

• else runs when no exception occurs.
• finally runs regardless—release resources there.
• Catch specific exceptions whenever possible.

Logging

import logging

logger = logging.getLogger(__name__)

try:
    process(order_id)
except Exception:
    logger.exception("Failed to process order %s", order_id)

logger.exception automatically includes the traceback. Call it inside an except block.

Next up in your learning path

Raise exceptions

Propagate errors intentionally.

Design

Custom exceptions

Model domain-specific failures.

Architecture

Common error fixes

Lookup guidance for frequent tracebacks.

Reference