類：通路限制

練習

請把下面的Student對象的gender字段對外隐藏起來，用get_gender()和set_gender()代替，并檢查參數有效性：

# -*- coding: utf-8 -*-

class Student(object):
    def __init__(self, name, gender):
        self.__name = name
        self.__gender = gender
    def set_gender(self,gender):
         if gender=='male'or gender=='female':
             self.__gender=gender
         else:
             raise TypeError("輸入性别錯誤")

    def get_gender(self):
        return self.__gender

# 測試:
bart = Student('Bart', 'male')
if bart.get_gender() != 'male':
    print('測試失敗!')
else:
    bart.set_gender('female')
    if bart.get_gender() != 'female':
        print('測試失敗!')
    else:
        print('測試成功!')
      

注意：

if gender=='male'or gender=='female':