在类中定义属性时，Python AttributeError对象没有属性

我正在使用Kivy编写一个实用平台，供我的同事在前台使用。我无法将用户分配到会话。这是我的密码：

masterControl.py

from kivy.uix.boxlayout import BoxLayout

class MasterControl(BoxLayout):
    def __init__(self, **kwargs):
        super(MasterControl, self).__init__(**kwargs)
        m_currentUser = None

    def loginUser(self, emp):
        self.m_currentUser = emp
        print "I made it to login!"
        # remove login widget, add the rest of the UI according to the security level of the use

login.py

from kivy.uix.anchorlayout import AnchorLayout 
from kivy.uix.label import Label
from kivy.uix.button import Button
from kivy.uix.textinput import TextInput
from kivy.uix.boxlayout import BoxLayout

from coreAPI.mastercontrol import MasterControl
from employee import Employee, getEmployees

class LoginWidget(AnchorLayout):
    def __init__(self, **kwargs):
        super(LoginWidget, self).__init__(**kwargs)

        def loginBtnHandle(instance):
            empList = getEmployees()
            for emp in empList:
                if emp.m_aNum == uNameInput.text:
                    if emp.authenticate(pWordInput.text):
                        self.parent.loginUser(emp) # Here is where I get  AttributeError: 'MasterControl' object has no attribute 'loginUser'

        box = BoxLayout(orientation = 'vertical', size = (300, 110), size_hint = (None, None), spacing = 10)

        uNameInput = TextInput(hint_text = 'Username', 
                multiline = False, 
                size = (300, 30), 
                size_hint = (None, None), 
                cursor_color = [0,0,0,1], 
                write_tab = False)

        pWordInput = TextInput(hint_text = 'Password', 
                multiline = False, 
                size = (300, 30), 
                size_hint = (None, None), 
                cursor_color = [0,0,0,1], 
                password = True, 
                write_tab = False)

        loginBtn = Button(text = 'Login', size = (300, 50), size_hint = (None, None))
        loginBtn.bind(on_press = loginBtnHandle)
        loginBtn.bind(on_enter = loginBtnHandle)

        box.add_widget(uNameInput)
        box.add_widget(pWordInput)
        box.add_widget(loginBtn)

        self.add_widget(box)

employee.py

from passlib.hash import pbkdf2_sha256
import pickle
import os

class Employee():
    def __init__(self, name, aNumber, password, clearance):
        self.m_name = name
        self.m_aNum = aNumber
        self.m_pWordHash = pbkdf2_sha256.hash(password) # Only store the password hash.  NEVER the password text
        self.m_clearance = clearance

    def authenticate(self, attempt):
        return pbkdf2_sha256.verify(attempt, self.m_pWordHash)

    def serialize(self):
        filename = 'users/' + self.m_aNum + '.emp'
        frozen = pickle.dumps(self)
        f = open(filename, 'w')
        f.write(frozen)
        f.close()
        return frozen

def getEmployees():
    empList = []
    path = 'users/'
    for filename in os.listdir(path):
        f = open(path + filename, 'r')
        contents = f.read()
        empList.append(pickle.loads(contents))
    return empList

tempEmp = Employee('Tester', 'A12345678', 'password', 'HIGH')
tempEmp.serialize()

用户通过身份验证后，登录小部件调用mastercontrol的

loginUser

方法。当它执行此操作时，Python抛出AttributeError:“MasterControl”对象没有属性“loginUser”。据我所知，它应该能够调用

logiuser

。我已经完成了缩进，并排除了导致employee对象反序列化错误的原因

问题

AttributeError:“MasterControl”对象没有属性“loginUser”

是由于未实例化MasterControl类造成的

解决 有两种解决办法。第一个解决方案假设MasterControl是根小部件。第二个解决方案假设LoginWidget是根小部件。有关详细信息，请参阅代码片段和输出

解决方案1-masterControl.py

从kivy.properties添加导入ObjectProperty

从登录添加导入登录Widget

将m_currentUser定义为ObjectProperty并将其初始化为None

将LoginWidget添加到MasterControl

片段 解决方案1-login.py

从coreAPI.mastercontrol中删除/注释导入mastercontrol

解决方案2-login.py

从kivy.properties添加导入ObjectProperty

定义对象属性，例如masterControl

实例化类MasterControl并将其连接到新的ObjectProperty MasterControl

将self.parent.login用户（emp）替换为self.masterControl.login用户（emp）

片段 解决方案2-masterControl.py

从kivy.properties添加导入ObjectProperty

将m_currentUser定义为ObjectProperty并将其初始化为None

片段 输出

---

您可以发布一个，我看不到MasterControl和LoginWidget之间有任何联系，可能创建了另一个MasterControl。在您的

MasterControl

init方法中，将

m\u currentUser=None

更改为

self.m\u currentUser=None

from kivy.properties import ObjectProperty

from login import LoginWidget


class MasterControl(BoxLayout):
    m_currentUser = ObjectProperty(None)

    def __init__(self, **kwargs):
        super(MasterControl, self).__init__(**kwargs)
        self.add_widget(LoginWidget())

from kivy.properties import ObjectProperty


class LoginWidget(AnchorLayout):
    masterControl = ObjectProperty(None)

    def __init__(self, **kwargs):
        super(LoginWidget, self).__init__(**kwargs)
        self.masterControl = MasterControl()

        def loginBtnHandle(instance):
            empList = getEmployees()
            for emp in empList:
                if emp.m_aNum == uNameInput.text:
                    if emp.authenticate(pWordInput.text):
                        self.masterControl.loginUser(emp)

from kivy.properties import ObjectProperty


class MasterControl(BoxLayout):
    m_currentUser = ObjectProperty(None)

    def __init__(self, **kwargs):
        super(MasterControl, self).__init__(**kwargs)

    def loginUser(self, emp):
        self.m_currentUser = emp