TypeError: Key id must be a string or a number

Question

I am trying to delete a key value from a list.So i created a method in my class like this:

def deleteEmployee(self, employee):
    employee_to_Delete = ndb.Key(Employee, employee)
    if employee_to_delete in self.employees:
        idx=self.employees.index(employee_to_delete)
        del self.employees[idx]
        self.put()

and then in the method where i am calling this method, i have something like

class DeleteEmployeeHandler(webapp2.RequestHandler):
def post(self):
    employee_name = self.request.get('employee_name')
    employee=Employee.get_by_id(employee_name)
    emp_dept=employee.department
    dept=Department.get_or_insert(emp_dept)
    dept.deleteEmployee(employee)
    employee.delete()

but I get the error message

TypeError: key id must be a string or a number. Can someone please tell me why this is happening?

Answer 1

employee is an instance of the Employee class, and you're passing that as the second parameter to ndb.Key. But the error message tells you exactly what's wrong: that parameter should be a string or an int, not an instance.

But, since you actually have the instance already, you don't need to construct a new Key: the employee object already has one, which you can use to delete.

employee_to_Delete = employee.key

Answer 2

The error you get is from google's datastore, not from Python's list.

You call ndb.Key(Employee, employee) and my guess is the employee you pass in is wrong type.