Python traceback.print_exc()返回'None'

Question

该函数应该捕获主执行中的异常.如果有异常,则应打印出错误log.error(traceback.print_exc())并清除exit_main().

def main():
    try:
        exec_app()
    except KeyboardInterrupt:
        log.error('Error: Backup aborted by user.')
        exit_main()
    except Exception:
        log.error('Error: An Exception was thrown.')
        log.error("-" * 60)
        log.error(traceback.print_exc())
        log.error("-" * 60)
        exit_main()

不幸的是log.error(traceback.print_exc()),只有None在有异常时才返回.在这种情况下,如何使回溯打印完整的错误报告？

PS:我使用python 3.4.

Answer 1

来自__doc__:

Shorthand for 'print_exception(sys.exc_type, sys.exc_value, sys.exc_traceback, limit, file)'

也就是说,它不应该返回任何东西,它的工作是打印.如果要将跟踪作为字符串记录,请traceback.format_exc()改用.