'NoneType' 和 'float' 的实例之间不支持 '>='

Question

我想运行我的代码，但是，我不断收到错误消息。 这是关于他们在其中输入值的表单字段。如果该值在特定范围内，他们将获得 1 欧元。代码是：

class Guess(Page):
    form_model = 'player'
    form_fields = ['guess']

    def is_displayed(self):
        return self.round_number == 2

    def vars_for_template(self):
        if self.player.guess >= 11.25 and self.player.guess <= 13.75:
            self.player.cumulative_guthaben = self.player.cumulative_guthaben + 1
        else:
            self.player.cumulative_guthaben = self.player.cumulative_guthaben

            return {
                'current_credit': self.player.cumulative_guthaben,
                'anzahlspieler': Constants.number_of_players,
                'round_number': self.round_number,}

我知道这是一个类型错误，但我没有成功修复它

Here is a shorter Version of my Class: 
class Player(BasePlayer): 
guthaben = models.CurrencyField(initial=c(0)) 
cumulative_guthaben = models.CurrencyField() 
donation = models.FloatField(min=c(0)) 
earnedmoney = models.CurrencyField() 
frequency = models.StringField() 
rival = models.StringField() 
guess = models.FloatField(label="Your Guess:")

Answer 1

您会收到错误，因为在某些时候 self.player.guess 是 NoneType 并且它应该是 float 以将其与 float 进行比较。您可以使用isinstance(i, type)。您不需要其他，因为您不会更改 self.player.cumulative_guthaben 的值。 但是您应该检查其余代码，为什么 self.player.guess 是 NoneType。 类似的东西：

class Guess(Page):
    form_model = 'player'
    form_fields = ['guess']
    def is_displayed(self):
        return self.round_number == 2

    def vars_for_template(self):
        if isinstance(self.player.guess, float):
            if (self.player.guess >= 11.25 and self.player.guess <= 13.75):
                self.player.cumulative_guthaben = self.player.cumulative_guthaben + 1
        return {
            'current_credit': self.player.cumulative_guthaben,
            'anzahlspieler': Constants.number_of_players,
            'round_number': self.round_number,}