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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def _get_log_format(self, request):
 """Return operation log format."""

        user = getattr(request, 'user', None)
        if not user:
            return
        if not request.user.is_authenticated:
            return
        method = request.method.upper()
        if not (method in self.target_methods):
            return
        request_url = urlparse.unquote(request.path)
        for rule in self._ignored_urls:
            if rule.search(request_url):
                return
        return self.format