python脚本demo

import atexit
import logging
import os
import signal
import sys
from logging.handlers import RotatingFileHandler



logger = logging.getLogger()
MAX = 10 * 1024 * 1024
BACK_UP_COUNT = 10
def setup_logging():
    log_file = os.path.join(r'C:\\',"demo.log")
    logger.setLevel(logging.INFO)
    file_handler = RotatingFileHandler(log_file,"a",MAX,BACK_UP_COUNT)
    file_handler.setFormatter(
        logging.Formatter(
            "[%(asctime)%s] [%(process)d] [%(levelname)s] - %(module)s.%(funcName)s"
            "(%(filename)s:%(lineno)d) - %(message)s"
        )
    )
    logger.addHandler(file_handler)
PID_FILE = "fmpid.pid"
def write_pid():
    with open(PID_FILE,"w") as f:
        f.write('%s\n'%(os.getpid()))

def read_pid():
    try:
        with open(PID_FILE) as f:
            pid = int(f.read().strip())
    except Exception:
        pid = None
    return pid

def remove_pid():
    if os.path.exists(PID_FILE):
        os.remove(PID_FILE)

def sig_handler(sig,frame):
    logger.warning("shutting down, got signal %d"%sig)
    remove_pid()
    sys.exit(0)

def setup_application():
    pid = read_pid()
    if pid:
        sys.stdout.write('processing is running...\n')
        sys.exit(0)
    setup_logging()
    write_pid()
    atexit.register(remove_pid)
    for sig in (signal.SIGTERM,signal.SIGINT):
        signal.signal(sig,sig_handler)

def main():
    setup_application()
    # 逻辑