6. Use except* for exception groups

When handling independent failures from concurrent work, use except* with exception groups.

Exception groups require you to think in terms of independent failures rather than one monolithic error path. except* expresses that model directly and lets you handle different error types without flattening away the structure of the group.

Note

Python 3.11+

6.1. Don’t do this

try:
    run_parallel_jobs()
except Exception as exc:
    for error in exc.exceptions:
        print(error)

6.2. Do this

try:
    run_parallel_jobs()
except* ValueError as exc_group:
    for error in exc_group.exceptions:
        print(error)