用于异常记录的Python记录器处理程序配置

Question

I have written this piece of code to get namespace from xml document. I am trying to handle exception, and write full trace to the log. however trace is not getting written with custom message in log (though i can see it on screen).

I believe, i am missing somthing in Logger handler config. is there any specific configuration we need to deal with? below is my logger config so far.

Any help will be appreciated.!

logger = logging.getLogger(__name__)
hdlr = logging.FileHandler(r'C:\link.log')
formatter = logging.Formatter('%(asctime)s %(levelname)s %(message)s')
hdlr.setFormatter(formatter)
logger.addHandler(hdlr)
logger.setLevel(logging.INFO)

def get_ns(xmlroot):
    """Retrieve XML Document Namespace """
    try:
        logger.info("Trying to get XML namespace detail")
        nsmap = xmlroot.nsmap.copy()
        logger.info("Creating XML Namespace Object, {0}".format(nsmap))
        nsmap['xmlns'] = nsmap.pop(None)
    except (KeyError, SystemExit):
        logging.exception("XML files does not contain namespace, Halting Program! ")
        sys.exit()
    else:
        for ns in nsmap.values():
            logger.info("Retrieved XML Namespace {0}".format(ns))
            return ns

output on screen:

ERROR:root:XML files does not contain namespace, Halting Program! 
Traceback (most recent call last):
  File "C:\link.log", line 28, in get_ns
    nsmap['xmlns'] = nsmap.pop(None)
KeyError: None

Answer 1

Change

logging.exception("XML files does not contain namespace, Halting Program! ")

to

logger.exception("XML files does not contain namespace, Halting Program! ")

Since it's logger that you have configured to write to file C:\\link.log .

Using logging.exception uses the "root logger", which outputs to the console by default.