strptime（）参数1必须是字符串，而不是类型Django

Question

我无法弄清楚这个应用程序出错的地方，试图验证日期是现在还是将来。但是我收到了有问题的错误。 这是错误：

class AppointmentManage(models.Manager):
    def appointvalidate(self,postData):
        errors={}
        pause=datetime.datetime.strptime(time,"%Y-%m-%d %H:%M")
        if len(postData['task'])<2:
            errors["Task field cannot be left blank"]="task"
        if len(postData['task'])<20:
            errors["Task field is too long"]="task"
        if len(postData['date'])<1:
            errors["Date field cannot be left blank"]="date"
        else:
            print "this is pause "
            print pause
        if pause<datetime.datetime.now():
                errors["Only present and future dates are permissable"]="date"
        if len(postData['time'])<1:
            errors["Time field cannot be left blank"]="time"
        return errors