{"library":"multiprocessing-logging","title":"Multiprocessing Logging","description":"Multiprocessing-logging is a Python library that provides a handler to centralize logging from child processes created by the `multiprocessing` module to the main process. This prevents log messages from becoming garbled when multiple processes attempt to write to the same stream or file concurrently. It currently supports Python 3.9+ and is primarily tested on Linux.","language":"python","status":"active","last_verified":"Sun May 17","install":{"commands":["pip install multiprocessing-logging"],"cli":null},"imports":["from multiprocessing_logging import install_mp_handler"],"auth":{"required":false,"env_vars":[]},"quickstart":{"code":"import logging\nimport multiprocessing\nimport time\nfrom multiprocessing_logging import install_mp_handler\nimport os\n\ndef worker_function(name):\n    logger = logging.getLogger()\n    logger.info(f\"Worker {name} starting (PID: {os.getpid()})\")\n    time.sleep(0.5) # Simulate work\n    logger.info(f\"Worker {name} finishing (PID: {os.getpid()})\")\n\nif __name__ == \"__main__\":\n    # Set up basic logging for the main process first\n    logging.basicConfig(\n        level=os.environ.get('LOG_LEVEL', 'INFO'),\n        format='%(asctime)s - %(processName)s - %(levelname)s - %(message)s'\n    )\n    logger = logging.getLogger()\n    logger.info(\"Main process starting.\")\n\n    # IMPORTANT: install_mp_handler BEFORE creating any worker processes or Pool\n    # This library only works with the 'fork' start method.\n    # On some systems (e.g., macOS Python 3.8+, Python 3.14+ on POSIX), \n    # 'fork' is not the default or is considered unsafe.\n    # You might need to explicitly set 'fork' if your system supports it:\n    # multiprocessing.set_start_method('fork', force=True)\n    \n    try:\n        install_mp_handler(logger=logger)\n        logger.info(\"Multiprocessing logging handler installed.\")\n\n        processes = []\n        for i in range(3):\n            p = multiprocessing.Process(target=worker_function, args=(f\"Task-{i}\",))\n            processes.append(p)\n            p.start()\n\n        for p in processes:\n            p.join()\n\n        logger.info(\"All worker processes completed.\")\n    except AssertionError as e:\n        logger.error(f\"Failed to install multiprocessing handler: {e}. Check multiprocessing start method.\")\n    except Exception as e:\n        logger.error(f\"An unexpected error occurred: {e}\")\n\n    logger.info(\"Main process finishing.\")","lang":"python","description":"This quickstart demonstrates how to set up `multiprocessing-logging` with Python's standard `logging` module. Configure your root logger with `logging.basicConfig` first, then call `install_mp_handler()` before any `multiprocessing.Process` or `multiprocessing.Pool` instances are created. Note the critical warning about the 'fork' start method requirement.","tag":null,"tag_description":null,"last_tested":null,"results":[]},"compatibility":{"tag":null,"tag_description":null,"last_tested":"2026-05-17","installed_version":"0.3.4","pypi_latest":"0.3.4","is_stale":false,"summary":{"python_range":"3.10–3.9","success_rate":100,"avg_install_s":1.5,"avg_import_s":0.05,"wheel_type":"wheel"},"results":[{"runtime":"python:3.10-alpine","python_version":"3.10","os_libc":"alpine (musl)","variant":"multiprocessing-logging","exit_code":0,"wheel_type":"wheel","failure_reason":null,"import_side_effects":"clean","install_time_s":null,"import_time_s":0.04,"mem_mb":1.4,"disk_size":"17.8M"},{"runtime":"python:3.10-slim","python_version":"3.10","os_libc":"slim (glibc)","variant":"multiprocessing-logging","exit_code":0,"wheel_type":"wheel","failure_reason":null,"import_side_effects":"clean","install_time_s":1.6,"import_time_s":0.03,"mem_mb":1.6,"disk_size":"18M"},{"runtime":"python:3.11-alpine","python_version":"3.11","os_libc":"alpine (musl)","variant":"multiprocessing-logging","exit_code":0,"wheel_type":"wheel","failure_reason":null,"import_side_effects":"clean","install_time_s":null,"import_time_s":0.07,"mem_mb":1.9,"disk_size":"19.7M"},{"runtime":"python:3.11-slim","python_version":"3.11","os_libc":"slim (glibc)","variant":"multiprocessing-logging","exit_code":0,"wheel_type":"wheel","failure_reason":null,"import_side_effects":"clean","install_time_s":1.6,"import_time_s":0.06,"mem_mb":1.9,"disk_size":"20M"},{"runtime":"python:3.12-alpine","python_version":"3.12","os_libc":"alpine (musl)","variant":"multiprocessing-logging","exit_code":0,"wheel_type":"wheel","failure_reason":null,"import_side_effects":"clean","install_time_s":null,"import_time_s":0.06,"mem_mb":1.7,"disk_size":"11.5M"},{"runtime":"python:3.12-slim","python_version":"3.12","os_libc":"slim (glibc)","variant":"multiprocessing-logging","exit_code":0,"wheel_type":"wheel","failure_reason":null,"import_side_effects":"clean","install_time_s":1.4,"import_time_s":0.06,"mem_mb":1.7,"disk_size":"12M"},{"runtime":"python:3.13-alpine","python_version":"3.13","os_libc":"alpine (musl)","variant":"multiprocessing-logging","exit_code":0,"wheel_type":"wheel","failure_reason":null,"import_side_effects":"clean","install_time_s":null,"import_time_s":0.07,"mem_mb":2,"disk_size":"11.3M"},{"runtime":"python:3.13-slim","python_version":"3.13","os_libc":"slim (glibc)","variant":"multiprocessing-logging","exit_code":0,"wheel_type":"wheel","failure_reason":null,"import_side_effects":"clean","install_time_s":1.4,"import_time_s":0.06,"mem_mb":1.8,"disk_size":"12M"},{"runtime":"python:3.9-alpine","python_version":"3.9","os_libc":"alpine (musl)","variant":"multiprocessing-logging","exit_code":0,"wheel_type":"wheel","failure_reason":null,"import_side_effects":"clean","install_time_s":null,"import_time_s":0.04,"mem_mb":1.4,"disk_size":"17.3M"},{"runtime":"python:3.9-slim","python_version":"3.9","os_libc":"slim (glibc)","variant":"multiprocessing-logging","exit_code":0,"wheel_type":"wheel","failure_reason":null,"import_side_effects":"clean","install_time_s":1.7,"import_time_s":0.04,"mem_mb":1.6,"disk_size":"18M"}]}}