１　使用log日志：

import logging
logging.basicConfig(level=logging.INFO, filename=＇mylog.log＇)

logging.info('start program')

print 1/0

logging.info('the division succeeded')

logging.info('Ending program')

2 使用输入输出流：

import sys

log_file = open('/tmp/py.log', 'a')
err_file = open('/tmp/py.err', 'a')

sys.stdout = log_file;
sys.stderr = log_err;

print('Hello')