No handlers could be found for logger “xhtml2pdf”

问题

I'm using xhtmltopdf.pisa for generating pdf from html template. The code was working fine.

pdf = pisa.pisaDocument(StringIO.StringIO(html.encode("UTF-8")), dest=result, link_callback=fetch_resources, default_css=open(pdf_css_path, 'r').read())

But some times I noticed that, the above code is not working. The error threw was No handlers could be found for logger "xhtml2pdf". Only some times I can find this error, but other times just works fine.

Any help is appreciated.

回答1:

The reason for the error is that, the pisa module some time uses the Python's logging module to log warnings or errors. By default it is trying to access a logger named xhtml2pdf. So you need to define a handler for xhtml2pdf on your settings file.

Django's logging settings would look like this,

LOGGING = {
    'version': 1,
    'disable_existing_loggers': True,
    'formatters': {
    'standard': {
        'format': "[%(asctime)s] %(levelname)s [%(name)s:%(lineno)s] %(message)s",
        'datefmt': "%d/%b/%Y %H:%M:%S"
        },
    },
    'handlers': {
        'logfile': {
            'level': 'DEBUG',
            'filename': BASE_DIR + "/Log/info.log"
        },
        'console': {
            'level': 'INFO',
            'class': 'logging.StreamHandler',
            'formatter': 'standard'
        },
    },
    'loggers': {
        'django': {
            'handlers': ['console'],
            'propagate': True,
            'level': 'WARN',
        },
        'xhtml2pdf': {
            'handlers': ['logfile'],
            'level': 'DEBUG'
       },
   }
}

The reason for this error's inconsistacy is bacause, pisa maynot use logger all the time.

来源：https://stackoverflow.com/questions/32997703/no-handlers-could-be-found-for-logger-xhtml2pdf