Context Manager

Backoff provides a context manager generator for non-decorator usage.

Basic Usage

import random

import backoff

for attempt in backoff.retry_context():
    with attempt:
        choice = random.choice("Lorem ipsum dolor sit amet")
        if choice not in "aeiou":
            raise RuntimeError(f"Ah, no luck! (choice={choice})")
        else:
            print(f"Got it (choice={choice})")

attempt is an instance of backoff.Attempt, so a helper that accepts one (e.g. for logging) can be typed against it directly:

from backoff import Attempt


def log_attempt(attempt: Attempt) -> None:
    print(f"exception so far: {attempt.exception}")


for attempt in backoff.retry_context():
    with attempt:
        log_attempt(attempt)
        # ...

Handlers passed as on_try/on_success/on_backoff/on_giveup receive a dict typed as backoff.types.ContextDetails:

from backoff.types import ContextDetails


def log_backoff(details: ContextDetails) -> None:
    print(f"retrying in {details['wait']}s after {details.get('exception')}")


for attempt in backoff.retry_context(on_backoff=log_backoff):
    with attempt:
        ...