Question

我正在尝试创建一个使用设置和Gui模块的用户系统，当gui模块请求使用pickle加载文件时，我不断收到属性错误。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，并被放入一个列表然后使用pickle保存列表，当我只加载设置文件并验证登录一切正常但是当我打开gui模块并尝试验证它不能让我，错误我得到：

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)>

Answer 1

问题在于您通过实际运行“设置”模块来在“设置”中定义的酸洗对象，然后您尝试从GUI模块中取消对象。< / p>

请记住，pickle实际上并不存储有关如何构造类/对象的信息，并且在unpickling时需要访问该类。有关详细信息，请参阅wiki on using Pickle。

在pkl数据中，您看到被引用的对象是__main__.Manager，因为创建pickle文件时“设置”模块是 main （即您运行了'设置' 'module作为调用addUser函数的主脚本。）

然后，您尝试在'Gui'中进行unpickling - 以便模块具有名称__main__，并且您正在该模块中导入Setting。当然，Manager类实际上是Settings.Manager。但是pkl文件不知道这一点，并在__main__中查找Manager类，并抛出AttributeError，因为它不存在（Settings.Manager但不存在，但__main__.Manager不存在）。

这是一个用于演示的最小代码集。

class_def.py模块：

import pickle class Foo(object): def __init__(self, name): self.name = name def main(): foo = Foo('a') with open('test_data.pkl', 'wb') as f: pickle.dump([foo], f, -1) if __name__=='__main__': main()

您运行以上操作以生成pickle数据。 main_module.py模块：

import pickle import class_def if __name__=='__main__': with open('test_data.pkl', 'rb') as f: users = pickle.load(f)

您运行以上操作以尝试打开pickle文件，这会抛出与您看到的大致相同的错误。（略有不同，但我猜这是因为我在Python 2.7上）

解决方案是：

通过显式导入使该类在顶级模块的命名空间（即GUI或main_module）中可用，或者

您可以从与其打开的模块相同的顶层模块创建pickle文件（即从GUI调用Settings.addUser或从main_module调用class_def.main）。这意味着pkl文件会将对象保存为Settings.Manager或class_def.Foo，然后可以在GUI`main_module`命名空间中找到它。

选项1示例：

import pickle import class_def from class_def import Foo # Import Foo into main_module's namespace explicitly if __name__=='__main__': with open('test_data.pkl', 'rb') as f: users = pickle.load(f)

选项2示例：

import pickle import class_def if __name__=='__main__': class_def.main() # Objects are being pickled with main_module as the top-level with open('test_data.pkl', 'rb') as f: users = pickle.load(f)

Answer 2

请先阅读zehnpaard提及的答案，以了解属性错误的原因。除了他已经提供的解决方案之外，在python3中，您可以使用pickle.Unpickler类并覆盖find_class方法，如下所述：

import pickle

class CustomUnpickler(pickle.Unpickler):

    def find_class(self, module, name):
        if name == 'Manager':
            from settings import Manager
            return Manager
        return super().find_class(module, name)

pickle_data = CustomUnpickler(open('file_path.pkl', 'rb')).load()

Answer 3

如果您使用 dill dump/load 模型将起作用

import dill
from sklearn.preprocessing import FunctionTransformer

sp_clf = FunctionTransformer(lambda X:X.astype('float').fillna(0).applymap(abs))

with open('temp.joblib','wb') as io:
    dill.dump(sp_clf,io)

with open('temp.joblib','rb') as io:
    dd=dill.load(io)

Answer 4

如果您在模块外部定义了一个类，其对象位于泡菜数据中，您必须导入课程

from outside_module import DefinedClass1, DefinedClass2, DefinedClass3 

with open('pickle_file.pkl', 'rb') as f:
    pickle_data = pickle.load(f)

Answer 5

如果即使在将适当的类导入到加载模块（zehnpaard's solution #1）中之后仍然出现此错误，则find_class的{{1}}函数可以被覆盖并显式定向到在当前模块的名称空间中查看。

pickle.Unpickler

注意：此方法将丢失存储在import pickle from settings import Manager class CustomUnpickler(pickle.Unpickler): def find_class(self, module, name): try: return super().find_class(__name__, name) except AttributeError: return super().find_class(module, name) pickle_data = CustomUnpickler(open('file_path.pkl', 'rb')).load() ## No exception trying to get 'Manager'中的相对导入路径信息。因此，请注意腌制类中的名称空间冲突。

无法使用pickle和多个模块加载文件

5 个答案: