deferred.defer显示PermanentTaskFailure:超过最大递归深度

Question

我试图从csv文件中导入所有数据，并将其作为csv文件存储到数据存储中。

__init__.py文件，其中定义了app。

@app.route("/import/<model>", methods=['POST'])
def import_csv(model):
    reader = UsersImporter(fil, user)
    reader.read()

importers.py

class UsersImporter(BaseImporter):
    def read(self):
        line = self.file.readline()
        self.checking_delimiter_on_first_line(line)
        self.file.seek(0)
        reader = csv.DictReader(self.file, delimiter=self.delimiter)
        try:
            for row in reader:
                deferred.defer(self.parse_line, row)
        except:
            print traceback.format_exc()
        self.insert_entities()

上面的代码会产生下面的回溯。

INFO     2016-12-26 08:00:09,745 deferred.py:303] X-Appengine-Current-Namespace:, X-Appengine-Taskexecutioncount:0, X-Appengine-Country:ZZ, X-Appengine-Taskname:task8, X-Appengine-Taskretrycount:0, X-Appengine-Queuename:default, X-Appengine-Tasketa:1482739209.69
ERROR    2016-12-26 08:00:09,749 deferred.py:319] Permanent failure attempting to execute task
Traceback (most recent call last):
  File "/home/gemini/softwares/google_appengine/google/appengine/ext/deferred/deferred.py", line 310, in post
    self.run_from_request()
  File "/home/gemini/softwares/google_appengine/google/appengine/ext/deferred/deferred.py", line 305, in run_from_request
    run(self.request.body)
  File "/home/gemini/softwares/google_appengine/google/appengine/ext/deferred/deferred.py", line 145, in run
    raise PermanentTaskFailure(e)
PermanentTaskFailure: maximum recursion depth exceeded

您知道，row不是requestHandler类的一个实例。self.parse_line也是在BaseImporter中定义的方法。

Answer 1

在将parse_line函数移出类后，它可以工作。例如，作为defferred.defer func的第一个参数传递的函数将不是实例方法。