Question

我在查询集结果中发生了一些非常奇怪的事情，我试图在Django项目中启动的线程中访问它。

出现的问题是在线程的 init 中一切正常，但是当我在run（）方法中完成应该是相同的操作时 - 它们返回空。代码和结果如下。

有关如何解决这种奇怪行为的任何想法都将不胜感激。

CODE：

class FinalDataCreator(threading.Thread):

    def __init__(self, final_form_entry, **kwargs):

            print "WORKS", final_form_entry.user_form_entries.all()

            self.final_form_entry = final_form_entry
            print "WORKS", self.final_form_entry.user_form_entries.all()

            self.weirdest_thing = self.final_form_entry.user_form_entries.all()

            self.jondykeman = "JonDykeman"

            super(FinalDataCreator, self).__init__(**kwargs)

        def run(self):

            print "EMPTY", self.final_form_entry.user_form_entries.all()

            print "EMPTY", self.weirdest_thing

            print "WORKS", self.jondykeman

            print "WORKS", self.final_form_entry

new_test = FinalDataCreator(final_form_entry)
new_test.start()

结果：

WORKS [<ReviewCustomFormEntry: ReviewCustomFormEntry object>]
WORKS [<ReviewCustomFormEntry: ReviewCustomFormEntry object>]
EMPTY []
EMPTY []
WORKS "JonDykeman"
WORKS ReviewCustomFormEntry

再次感谢JD

Answer 1

如果您在Python27 \ lib \ threading.py中阅读了线程类的文档，它会说......

If a subclass overrides the constructor, it must make sure to invoke
the base class constructor (Thread.__init__()) before doing anything
else to the thread.

所以改变你的代码，如

class FinalDataCreator(threading.Thread):

def __init__(self, final_form_entry, **kwargs):

        super(FinalDataCreator, self).__init__(**kwargs) #why you need to pass **kwargs

        print "WORKS", final_form_entry.user_form_entries.all()

        self.final_form_entry = final_form_entry
        print "WORKS", self.final_form_entry.user_form_entries.all()

        self.weirdest_thing = self.final_form_entry.user_form_entries.all()

    def run(self):

        print "EMPTY", self.final_form_entry.user_form_entries.all()

        print "EMPTY", self.weirdest_thing

然后运行您的代码

奇怪的django ORM行为与线程

1 个答案: