明天的内容包含if语句以及字典的操作。
# 查看是否不相等requested_topping = 'mushrooms'if requested_topping != 'anchovies': print("hold the anchovies")# 查看特定值是否蕴含在列表中requested_toppings = ['1', '2', '3']if '1' in requested_toppings: print('true')banned_users = ['andrew', 'caroline', 'david']user = 'marie'if user not in banned_users: print(user.title() + ', you can post a response if you wish.')# if-elif-else 确定列表不是空的requested_toppings = []if requested_toppings: # 列表空等于False for requested_topping in requested_toppings: print("adding" + requested_topping + ".") print("\nFinished making your pizza!")else: print("Are you sure you want a plain pizza?")# 创立字典alien_0 = {'color':'green', 'points':5}print(alien_0['color'])print(alien_0['points'])# 增加键-值对alien_0['x_position'] = 0alien_0['y_position'] = 25print(alien_0)# 批改键-值对alien_0['color'] = 'yellow'print(alien_0)# 删除键-值对del alien_0['points']print(alien_0) # 删除的键值对永远隐没了# 遍历字典所有的键-值对for key, value in alien_0.items(): # items()返回一对键-值对 print("\nKey: " + key) print("Value: " + str(value))# 遍历字典所有的键for name in alien_0.keys(): # keys()返回键 value()返回值 print(name.title())# 应用set()办法找出举世无双的元素trial_0 = { '1': '11', '2': '22', '3': '22', }print('The following item is unique: ')for number in set(trial_0.values()): print(number.title())# 字典列表trial_1 = {'4':'44'}trial_2 = {'5':'55'}trial_3 = {'6':'66'}Trial = [trial_1, trial_2, trial_3]for ttrial in Trial: print(ttrial)# 在字典中存储列表trial_4 = { 'crust': 'thick', 'toppings': ['mushroom', 'extra cheese']}print(trial_4['crust'])print(trial_4['toppings'])for topping in trial_4['toppings']: print('\t' + topping)# 在字典中存储字典，操作方法相似，省略整体运行后果：
hold the anchoviestrueMarie, you can post a response if you wish.Are you sure you want a plain pizza?green5{'color': 'green', 'points': 5, 'x_position': 0, 'y_position': 25}{'color': 'yellow', 'points': 5, 'x_position': 0, 'y_position': 25}{'color': 'yellow', 'x_position': 0, 'y_position': 25}Key: colorValue: yellowKey: x_positionValue: 0Key: y_positionValue: 25ColorX_PositionY_PositionThe following item is unique: 1122{'4': '44'}{'5': '55'}{'6': '66'}thick['mushroom', 'extra cheese'] mushroom extra cheese