Python ImportError:无法导入名称验证\u会话

我正在尝试构建一个简单的计算器，但是我得到了

ImportError:cannotimportname-verify\u session

我猜这是某种循环导入，但我不确定如何修复此类错误

文件夹结构

/calculator
/--app.py
/--decorators.py

app.py

from decorators import verify_session


class InvalidAmountException(Exception):
    pass


class InvalidSessionException(Exception):
    pass


class Calculator(object):
    def __init__(self):
        self.amount = 150
        self.password = 'randompass123'
        self.session = False

    def __check_balance(self, amount):
        if self.amount - amount < 0:
            raise InvalidAmountException
        return True

    def kill(self):
        self.session = False
        return self.session

    @verify_session
    def withdrawal(self, amount):
        try:
            self.__check_balance(amount)
            self.amount -= amount
        except InvalidAmountException:
            print 'Sum amount not avaliable!'

    def deposit(self, amount):
        self.amount += amount

    def get_amount(self):
        return self.amount


if __name__ == '__main__':
    m = Calculator()
    m.deposit(150)
    m.withdrawal(21)
    m.withdrawal(2451)

from app import InvalidSessionException

def verify_session(func):
    def func_wrapper(self, *args, **kwargs):
        if not self.session:
            raise InvalidSessionException

    return func_wrapper

class InvalidAmountException(Exception):
    pass

class InvalidSessionException(Exception):
    pass

from decorators import verify_session

from myExceptions import InvalidAmountException, InvalidSessionException

...

from myExceptions import InvalidSessionException

...

---

没错，您看到app.py和decorators.py之间存在循环依赖关系

我建议将异常从app.py移到它们自己的文件中，例如myExceptions.py，然后将它们导入app.py和decorators.py

myExceptions.py

from decorators import verify_session


class InvalidAmountException(Exception):
    pass


class InvalidSessionException(Exception):
    pass


class Calculator(object):
    def __init__(self):
        self.amount = 150
        self.password = 'randompass123'
        self.session = False

    def __check_balance(self, amount):
        if self.amount - amount < 0:
            raise InvalidAmountException
        return True

    def kill(self):
        self.session = False
        return self.session

    @verify_session
    def withdrawal(self, amount):
        try:
            self.__check_balance(amount)
            self.amount -= amount
        except InvalidAmountException:
            print 'Sum amount not avaliable!'

    def deposit(self, amount):
        self.amount += amount

    def get_amount(self):
        return self.amount


if __name__ == '__main__':
    m = Calculator()
    m.deposit(150)
    m.withdrawal(21)
    m.withdrawal(2451)

from app import InvalidSessionException

def verify_session(func):
    def func_wrapper(self, *args, **kwargs):
        if not self.session:
            raise InvalidSessionException

    return func_wrapper

class InvalidAmountException(Exception):
    pass

class InvalidSessionException(Exception):
    pass

from decorators import verify_session

from myExceptions import InvalidAmountException, InvalidSessionException

...

from myExceptions import InvalidSessionException

...

app.py

from decorators import verify_session


class InvalidAmountException(Exception):
    pass


class InvalidSessionException(Exception):
    pass


class Calculator(object):
    def __init__(self):
        self.amount = 150
        self.password = 'randompass123'
        self.session = False

    def __check_balance(self, amount):
        if self.amount - amount < 0:
            raise InvalidAmountException
        return True

    def kill(self):
        self.session = False
        return self.session

    @verify_session
    def withdrawal(self, amount):
        try:
            self.__check_balance(amount)
            self.amount -= amount
        except InvalidAmountException:
            print 'Sum amount not avaliable!'

    def deposit(self, amount):
        self.amount += amount

    def get_amount(self):
        return self.amount


if __name__ == '__main__':
    m = Calculator()
    m.deposit(150)
    m.withdrawal(21)
    m.withdrawal(2451)

from app import InvalidSessionException

def verify_session(func):
    def func_wrapper(self, *args, **kwargs):
        if not self.session:
            raise InvalidSessionException

    return func_wrapper

class InvalidAmountException(Exception):
    pass

class InvalidSessionException(Exception):
    pass

from decorators import verify_session

from myExceptions import InvalidAmountException, InvalidSessionException

...

from myExceptions import InvalidSessionException

...

decorators.py

from decorators import verify_session


class InvalidAmountException(Exception):
    pass


class InvalidSessionException(Exception):
    pass


class Calculator(object):
    def __init__(self):
        self.amount = 150
        self.password = 'randompass123'
        self.session = False

    def __check_balance(self, amount):
        if self.amount - amount < 0:
            raise InvalidAmountException
        return True

    def kill(self):
        self.session = False
        return self.session

    @verify_session
    def withdrawal(self, amount):
        try:
            self.__check_balance(amount)
            self.amount -= amount
        except InvalidAmountException:
            print 'Sum amount not avaliable!'

    def deposit(self, amount):
        self.amount += amount

    def get_amount(self):
        return self.amount


if __name__ == '__main__':
    m = Calculator()
    m.deposit(150)
    m.withdrawal(21)
    m.withdrawal(2451)

from app import InvalidSessionException

def verify_session(func):
    def func_wrapper(self, *args, **kwargs):
        if not self.session:
            raise InvalidSessionException

    return func_wrapper

class InvalidAmountException(Exception):
    pass

class InvalidSessionException(Exception):
    pass

from decorators import verify_session

from myExceptions import InvalidAmountException, InvalidSessionException

...

from myExceptions import InvalidSessionException

...

---

没错，您看到app.py和decorators.py之间存在循环依赖关系

我建议将异常从app.py移到它们自己的文件中，例如myExceptions.py，然后将它们导入app.py和decorators.py

myExceptions.py

from decorators import verify_session


class InvalidAmountException(Exception):
    pass


class InvalidSessionException(Exception):
    pass


class Calculator(object):
    def __init__(self):
        self.amount = 150
        self.password = 'randompass123'
        self.session = False

    def __check_balance(self, amount):
        if self.amount - amount < 0:
            raise InvalidAmountException
        return True

    def kill(self):
        self.session = False
        return self.session

    @verify_session
    def withdrawal(self, amount):
        try:
            self.__check_balance(amount)
            self.amount -= amount
        except InvalidAmountException:
            print 'Sum amount not avaliable!'

    def deposit(self, amount):
        self.amount += amount

    def get_amount(self):
        return self.amount


if __name__ == '__main__':
    m = Calculator()
    m.deposit(150)
    m.withdrawal(21)
    m.withdrawal(2451)

from app import InvalidSessionException

def verify_session(func):
    def func_wrapper(self, *args, **kwargs):
        if not self.session:
            raise InvalidSessionException

    return func_wrapper

class InvalidAmountException(Exception):
    pass

class InvalidSessionException(Exception):
    pass

from decorators import verify_session

from myExceptions import InvalidAmountException, InvalidSessionException

...

from myExceptions import InvalidSessionException

...

app.py

from decorators import verify_session


class InvalidAmountException(Exception):
    pass


class InvalidSessionException(Exception):
    pass


class Calculator(object):
    def __init__(self):
        self.amount = 150
        self.password = 'randompass123'
        self.session = False

    def __check_balance(self, amount):
        if self.amount - amount < 0:
            raise InvalidAmountException
        return True

    def kill(self):
        self.session = False
        return self.session

    @verify_session
    def withdrawal(self, amount):
        try:
            self.__check_balance(amount)
            self.amount -= amount
        except InvalidAmountException:
            print 'Sum amount not avaliable!'

    def deposit(self, amount):
        self.amount += amount

    def get_amount(self):
        return self.amount


if __name__ == '__main__':
    m = Calculator()
    m.deposit(150)
    m.withdrawal(21)
    m.withdrawal(2451)

from app import InvalidSessionException

def verify_session(func):
    def func_wrapper(self, *args, **kwargs):
        if not self.session:
            raise InvalidSessionException

    return func_wrapper

class InvalidAmountException(Exception):
    pass

class InvalidSessionException(Exception):
    pass

from decorators import verify_session

from myExceptions import InvalidAmountException, InvalidSessionException

...

from myExceptions import InvalidSessionException

...

decorators.py

from decorators import verify_session


class InvalidAmountException(Exception):
    pass


class InvalidSessionException(Exception):
    pass


class Calculator(object):
    def __init__(self):
        self.amount = 150
        self.password = 'randompass123'
        self.session = False

    def __check_balance(self, amount):
        if self.amount - amount < 0:
            raise InvalidAmountException
        return True

    def kill(self):
        self.session = False
        return self.session

    @verify_session
    def withdrawal(self, amount):
        try:
            self.__check_balance(amount)
            self.amount -= amount
        except InvalidAmountException:
            print 'Sum amount not avaliable!'

    def deposit(self, amount):
        self.amount += amount

    def get_amount(self):
        return self.amount


if __name__ == '__main__':
    m = Calculator()
    m.deposit(150)
    m.withdrawal(21)
    m.withdrawal(2451)

from app import InvalidSessionException

def verify_session(func):
    def func_wrapper(self, *args, **kwargs):
        if not self.session:
            raise InvalidSessionException

    return func_wrapper

class InvalidAmountException(Exception):
    pass

class InvalidSessionException(Exception):
    pass

from decorators import verify_session

from myExceptions import InvalidAmountException, InvalidSessionException

...

from myExceptions import InvalidSessionException

...

---

没错，您看到app.py和decorators.py之间存在循环依赖关系

我建议将异常从app.py移到它们自己的文件中，例如myExceptions.py，然后将它们导入app.py和decorators.py

myExceptions.py

from decorators import verify_session


class InvalidAmountException(Exception):
    pass


class InvalidSessionException(Exception):
    pass


class Calculator(object):
    def __init__(self):
        self.amount = 150
        self.password = 'randompass123'
        self.session = False

    def __check_balance(self, amount):
        if self.amount - amount < 0:
            raise InvalidAmountException
        return True

    def kill(self):
        self.session = False
        return self.session

    @verify_session
    def withdrawal(self, amount):
        try:
            self.__check_balance(amount)
            self.amount -= amount
        except InvalidAmountException:
            print 'Sum amount not avaliable!'

    def deposit(self, amount):
        self.amount += amount

    def get_amount(self):
        return self.amount


if __name__ == '__main__':
    m = Calculator()
    m.deposit(150)
    m.withdrawal(21)
    m.withdrawal(2451)

from app import InvalidSessionException

def verify_session(func):
    def func_wrapper(self, *args, **kwargs):
        if not self.session:
            raise InvalidSessionException

    return func_wrapper

class InvalidAmountException(Exception):
    pass

class InvalidSessionException(Exception):
    pass

from decorators import verify_session

from myExceptions import InvalidAmountException, InvalidSessionException

...

from myExceptions import InvalidSessionException

...

app.py

from decorators import verify_session


class InvalidAmountException(Exception):
    pass


class InvalidSessionException(Exception):
    pass


class Calculator(object):
    def __init__(self):
        self.amount = 150
        self.password = 'randompass123'
        self.session = False

    def __check_balance(self, amount):
        if self.amount - amount < 0:
            raise InvalidAmountException
        return True

    def kill(self):
        self.session = False
        return self.session

    @verify_session
    def withdrawal(self, amount):
        try:
            self.__check_balance(amount)
            self.amount -= amount
        except InvalidAmountException:
            print 'Sum amount not avaliable!'

    def deposit(self, amount):
        self.amount += amount

    def get_amount(self):
        return self.amount


if __name__ == '__main__':
    m = Calculator()
    m.deposit(150)
    m.withdrawal(21)
    m.withdrawal(2451)

from app import InvalidSessionException

def verify_session(func):
    def func_wrapper(self, *args, **kwargs):
        if not self.session:
            raise InvalidSessionException

    return func_wrapper

class InvalidAmountException(Exception):
    pass

class InvalidSessionException(Exception):
    pass

from decorators import verify_session

from myExceptions import InvalidAmountException, InvalidSessionException

...

from myExceptions import InvalidSessionException

...

decorators.py

from decorators import verify_session


class InvalidAmountException(Exception):
    pass


class InvalidSessionException(Exception):
    pass


class Calculator(object):
    def __init__(self):
        self.amount = 150
        self.password = 'randompass123'
        self.session = False

    def __check_balance(self, amount):
        if self.amount - amount < 0:
            raise InvalidAmountException
        return True

    def kill(self):
        self.session = False
        return self.session

    @verify_session
    def withdrawal(self, amount):
        try:
            self.__check_balance(amount)
            self.amount -= amount
        except InvalidAmountException:
            print 'Sum amount not avaliable!'

    def deposit(self, amount):
        self.amount += amount

    def get_amount(self):
        return self.amount


if __name__ == '__main__':
    m = Calculator()
    m.deposit(150)
    m.withdrawal(21)
    m.withdrawal(2451)

from app import InvalidSessionException

def verify_session(func):
    def func_wrapper(self, *args, **kwargs):
        if not self.session:
            raise InvalidSessionException

    return func_wrapper

class InvalidAmountException(Exception):
    pass

class InvalidSessionException(Exception):
    pass

from decorators import verify_session

from myExceptions import InvalidAmountException, InvalidSessionException

...

from myExceptions import InvalidSessionException

...

---

没错，您看到app.py和decorators.py之间存在循环依赖关系

我建议将异常从app.py移到它们自己的文件中，例如myExceptions.py，然后将它们导入app.py和decorators.py

myExceptions.py

from decorators import verify_session


class InvalidAmountException(Exception):
    pass


class InvalidSessionException(Exception):
    pass


class Calculator(object):
    def __init__(self):
        self.amount = 150
        self.password = 'randompass123'
        self.session = False

    def __check_balance(self, amount):
        if self.amount - amount < 0:
            raise InvalidAmountException
        return True

    def kill(self):
        self.session = False
        return self.session

    @verify_session
    def withdrawal(self, amount):
        try:
            self.__check_balance(amount)
            self.amount -= amount
        except InvalidAmountException:
            print 'Sum amount not avaliable!'

    def deposit(self, amount):
        self.amount += amount

    def get_amount(self):
        return self.amount


if __name__ == '__main__':
    m = Calculator()
    m.deposit(150)
    m.withdrawal(21)
    m.withdrawal(2451)

from app import InvalidSessionException

def verify_session(func):
    def func_wrapper(self, *args, **kwargs):
        if not self.session:
            raise InvalidSessionException

    return func_wrapper

class InvalidAmountException(Exception):
    pass

class InvalidSessionException(Exception):
    pass

from decorators import verify_session

from myExceptions import InvalidAmountException, InvalidSessionException

...

from myExceptions import InvalidSessionException

...

app.py

from decorators import verify_session


class InvalidAmountException(Exception):
    pass


class InvalidSessionException(Exception):
    pass


class Calculator(object):
    def __init__(self):
        self.amount = 150
        self.password = 'randompass123'
        self.session = False

    def __check_balance(self, amount):
        if self.amount - amount < 0:
            raise InvalidAmountException
        return True

    def kill(self):
        self.session = False
        return self.session

    @verify_session
    def withdrawal(self, amount):
        try:
            self.__check_balance(amount)
            self.amount -= amount
        except InvalidAmountException:
            print 'Sum amount not avaliable!'

    def deposit(self, amount):
        self.amount += amount

    def get_amount(self):
        return self.amount


if __name__ == '__main__':
    m = Calculator()
    m.deposit(150)
    m.withdrawal(21)
    m.withdrawal(2451)

from app import InvalidSessionException

def verify_session(func):
    def func_wrapper(self, *args, **kwargs):
        if not self.session:
            raise InvalidSessionException

    return func_wrapper

class InvalidAmountException(Exception):
    pass

class InvalidSessionException(Exception):
    pass

from decorators import verify_session

from myExceptions import InvalidAmountException, InvalidSessionException

...

from myExceptions import InvalidSessionException

...

decorators.py

from decorators import verify_session


class InvalidAmountException(Exception):
    pass


class InvalidSessionException(Exception):
    pass


class Calculator(object):
    def __init__(self):
        self.amount = 150
        self.password = 'randompass123'
        self.session = False

    def __check_balance(self, amount):
        if self.amount - amount < 0:
            raise InvalidAmountException
        return True

    def kill(self):
        self.session = False
        return self.session

    @verify_session
    def withdrawal(self, amount):
        try:
            self.__check_balance(amount)
            self.amount -= amount
        except InvalidAmountException:
            print 'Sum amount not avaliable!'

    def deposit(self, amount):
        self.amount += amount

    def get_amount(self):
        return self.amount


if __name__ == '__main__':
    m = Calculator()
    m.deposit(150)
    m.withdrawal(21)
    m.withdrawal(2451)

from app import InvalidSessionException

def verify_session(func):
    def func_wrapper(self, *args, **kwargs):
        if not self.session:
            raise InvalidSessionException

    return func_wrapper

class InvalidAmountException(Exception):
    pass

class InvalidSessionException(Exception):
    pass

from decorators import verify_session

from myExceptions import InvalidAmountException, InvalidSessionException

...

from myExceptions import InvalidSessionException

...

---

@埃里克的建议奏效了。我已经创建了myExceptions.py文件 并将自定义异常类移到了那里。请检查以下代码：

#myexceptions.py

class InvalidAmountException(Exception):
    pass


class InvalidSessionException(Exception):
    pass

#Modified a code bit in decorators.py

from myexceptions import InvalidSessionException

def verify_session(func):
    def func_wrapper(self, *args, **kwargs):
        try:
            if not self.session:
            raise InvalidSessionException
        except InvalidSessionException:
        print "Invalid session. Logging off..."
    return func_wrapper

#When I executed app.py my output is looking like this...

E:\calc>python app.py
Invalid session. Logging off...
Invalid session. Logging off...

E:\calc>

---

@埃里克的建议奏效了。我已经创建了myExceptions.py文件 并将自定义异常类移到了那里。请检查以下代码：

#myexceptions.py

class InvalidAmountException(Exception):
    pass


class InvalidSessionException(Exception):
    pass

#Modified a code bit in decorators.py

from myexceptions import InvalidSessionException

def verify_session(func):
    def func_wrapper(self, *args, **kwargs):
        try:
            if not self.session:
            raise InvalidSessionException
        except InvalidSessionException:
        print "Invalid session. Logging off..."
    return func_wrapper

#When I executed app.py my output is looking like this...

E:\calc>python app.py
Invalid session. Logging off...
Invalid session. Logging off...

E:\calc>

---

@埃里克的建议奏效了。我已经创建了myExceptions.py文件 并将自定义异常类移到了那里。请检查以下代码：

#myexceptions.py

class InvalidAmountException(Exception):
    pass


class InvalidSessionException(Exception):
    pass

#Modified a code bit in decorators.py

from myexceptions import InvalidSessionException

def verify_session(func):
    def func_wrapper(self, *args, **kwargs):
        try:
            if not self.session:
            raise InvalidSessionException
        except InvalidSessionException:
        print "Invalid session. Logging off..."
    return func_wrapper

#When I executed app.py my output is looking like this...

E:\calc>python app.py
Invalid session. Logging off...
Invalid session. Logging off...

E:\calc>

---

@埃里克的建议奏效了。我已经创建了myExceptions.py文件 并将自定义异常类移到了那里。请检查以下代码：

#myexceptions.py

class InvalidAmountException(Exception):
    pass


class InvalidSessionException(Exception):
    pass

#Modified a code bit in decorators.py

from myexceptions import InvalidSessionException

def verify_session(func):
    def func_wrapper(self, *args, **kwargs):
        try:
            if not self.session:
            raise InvalidSessionException
        except InvalidSessionException:
        print "Invalid session. Logging off..."
    return func_wrapper

#When I executed app.py my output is looking like this...

E:\calc>python app.py
Invalid session. Logging off...
Invalid session. Logging off...

E:\calc>

---

这是我的第一次，但还是不起作用。在这种情况下，我在

decorators.py

中得到了

ImportError:cannotimport name InvalidSessionException

，我将用一个简短的示例更新我的答案，这个示例可能会更清楚，同时也会为异常文件建议一个不同的名称，以避免与内置异常类发生任何潜在的命名空间冲突。你说得对。名字就是问题所在。一旦我改变了它，一切都很好，虽然这是我的第一次，但它仍然不起作用。在这种情况下，我在

decorators.py

中得到了

ImportError:cannotimport name InvalidSessionException

，我将用一个简短的示例更新我的答案，这个示例可能会更清楚，同时也会为异常文件建议一个不同的名称，以避免与内置异常类发生任何潜在的命名空间冲突。你说得对。名字就是问题所在。一旦我改变了它，一切都很好，虽然这是我的第一次，但它仍然不起作用。在这种情况下，我在

decorators.py

中得到了

ImportError:cannotimport name InvalidSessionException

，我将用一个简短的示例更新我的答案，这个示例可能会更清楚，同时也会为异常文件建议一个不同的名称，以避免与内置异常类发生任何潜在的命名空间冲突。你说得对。名字就是问题所在。一旦我改变了它，一切都很好，虽然这是我的第一次，但它仍然不起作用。在这种情况下，我在

decorators.py

中得到了

ImportError:cannotimport name InvalidSessionException

，我将用一个简短的示例更新我的答案，这个示例可能会更清楚，同时也会为异常文件建议一个不同的名称，以避免与内置异常类发生任何潜在的命名空间冲突。你说得对。名字就是问题所在。一旦我改变了它，一切都很好