refire

A flexible Python decorator for retrying functions upon failure with support for exponential backoff, jitter, and configurable retry policies.

Features

• Retry functions automatically when exceptions occur.
• Configurable number of retries or infinite retries.
• Adjustable initial delay and exponential backoff.
• Optional maximum delay to cap wait times.
• Support for random jitter to prevent retry storms (thundering herd problem).
• Specify which exception types trigger retries.

Installation

Install via pip:

pip install refire
# or
uv add refire

Or clone the repository:

git clone https://github.com/maxscheijen/refire.git
cd refire
pip install .
# or
uv sync

Usage

Basic Example

import random

from refire import refire


@refire(tries=5, delay=2, backoff=2, jitter=(0, 1))
def flaky_function():
    if random.random() < 0.7:
        raise ValueError("Unlucky!")
    return "Success!"

result = flaky_function()
print(result)  # "Success!" after several retries

Custom Exception

class CustomError(Exception):
    pass

@refire(exceptions=CustomError, tries=3, delay=1)
def risky_function():
    raise CustomError("Oops!")

risky_function()

Logging

Retries are by default logged at WARNING level:

Caught ValueError: Unlucky!. Retrying in 2.00s (remaining=4)

Development

This project uses uv. To set up a local development environment:

# Clone the repository
git clone https://github.com/maxscheijen/refire.git
cd refire

# Install dependencies (using uv)
uv sync --extra dev

# Or using pip
pip install -e ".[dev]"

Tests

This project uses pytest:

pytest