无法使用 pickle 和多个模块加载文件

我正在尝试创建一个用户系统，它使用一个设置和 GUI 模块，当 GUI 模块请求使用 pickle 加载文件时，我总是得到一个属性错误。这是来自设置模块:

import pickle
import hashlib


class User(object):
def __init__(self, fname, lname, dob, gender):
self.firstname = fname
self.lastname = lname
self._dob = dob
self.gender = gender
self.type = 'General'
self._username = ''
self._hashkey = ''


def Report(self):
print("Full Name: {0} {1}\nDate of Birth: {2}\nGender: {3}\nAccess Level: {4}".format(self.firstname,self.lastname, self._dob, self.gender, self.type))
print(self._username)


def Genusername(self):
self._username = str(str(self._dob)[:2] + self.firstname[:2] + self.lastname[:2])
saveUsers(users)


def Genhashkey(self, password):
encoded = password.encode('utf-8','strict')
return hashlib.sha256(encoded).hexdigest()


def Verifypassword(self, password):
if self._hashkey == self.Genhashkey(password):
return True
else:
return False


class SAdmin(User):
def __init__(self, fname, lname, dob, gender):
super().__init__(fname, lname, dob, gender)
self.type = 'Stock Admin'


class Manager(User):
def __init__(self, fname, lname, dob, gender):
super().__init__(fname, lname, dob, gender)
self.type = 'Manager'


def saveUsers(users):
with open('user_data.pkl', 'wb') as file:
pickle.dump(users, file, -1) # PICKLE HIGHEST LEVEL PROTOCOL


def loadUsers(users):
try:
with open('user_data.pkl', 'rb') as file:
temp = pickle.load(file)
for item in temp:
users.append(item)
except IOError:
saveUsers([])


def userReport(users):
for user in users:
print(user.firstname, user.lastname)


def addUser(users):
fname = input('What is your First Name?\n > ')
lname = input('What is your Last Name?\n > ')
dob = int(input('Please enter your date of birth in the following format, example 12211996\n> '))
gender = input("What is your gender? 'M' or 'F'\n >")
level = input("Enter the access level given to this user 'G', 'A', 'M'\n > ")
password = input("Enter a password:\n > ")
if level == 'G':
usertype = User
if level == 'A':
usertype = SAdmin
if level == 'M':
usertype = Manager
users.append(usertype(fname, lname, dob, gender))
user = users[len(users)-1]
user.Genusername()
user._hashkey = user.Genhashkey(password)
saveUsers(users)


def deleteUser(users):
userReport(users)
delete = input('Please type in the First Name of the user do you wish to delete:\n > ')
for user in users:
if user.firstname == delete:
users.remove(user)
saveUsers(users)


def changePass(users):
userReport(users)
change = input('Please type in the First Name of the user you wish to change the password for :\n > ')
for user in users:
if user.firstname == change:
oldpass = input('Please type in your old password:\n > ')
newpass = input('Please type in your new password:\n > ')
if user.Verifypassword(oldpass):
user._hashkey = user.Genhashkey(newpass)
saveUsers(users)
else:
print('Your old password does not match!')


def verifyUser(username, password):
for user in users:
if user._username == username and user.Verifypassword(password):
return True
else:
return False


if __name__ == '__main__':
users = []
loadUsers(users)

这是 GUI 模块:

from PyQt4 import QtGui, QtCore
import Settings


class loginWindow(QtGui.QDialog):
def __init__(self):
super().__init__()
self.initUI()


def initUI(self):
self.lbl1 = QtGui.QLabel('Username')
self.lbl2 = QtGui.QLabel('Password')
self.username = QtGui.QLineEdit()
self.password = QtGui.QLineEdit()


self.okButton = QtGui.QPushButton("OK")
self.okButton.clicked.connect(self.tryLogin)
self.cancelButton = QtGui.QPushButton("Cancel")


grid = QtGui.QGridLayout()
grid.setSpacing(10)


grid.addWidget(self.lbl1, 1, 0)
grid.addWidget(self.username, 1, 1)
grid.addWidget(self.lbl2, 2, 0)
grid.addWidget(self.password, 2, 1)
grid.addWidget(self.okButton, 3, 1)
grid.addWidget(self.cancelButton, 3, 0)


self.setLayout(grid)


self.setGeometry(300, 300, 2950, 150)
self.setWindowTitle('Login')
self.show()


def tryLogin(self):
print(self.username.text(), self.password.text())
if Settings.verifyUser(self.username.text(),self.password.text()):
print('it Woks')
else:
QtGui.QMessageBox.warning(
self, 'Error', 'Incorrect Username or Password')


class Window(QtGui.QMainWindow):
def __init__(self):
super().__init__()




if __name__ == '__main__':


app = QtGui.QApplication(sys.argv)
users = []
Settings.loadUsers(users)
if loginWindow().exec_() == QtGui.QDialog.Accepted:
window = Window()
window.show()
sys.exit(app.exec_())

每个用户都是一个类，被放到一个列表中，然后列表被 pickle 保存，当我加载设置文件并验证登录时，一切正常，但是当我打开 GUI 模块并尝试验证它不允许时，我得到的错误是:

Traceback (most recent call last):
File "C:\Users`Program\LoginGUI.py", line 53, in <module>
Settings.loadUsers(users)
File "C:\Users\Program\Settings.py", line 51, in loadUsers
temp = pickle.load(file)
AttributeError: Can't get attribute 'Manager' on <module '__main__' (built-in)>