Python 学习笔记之字典

alien_0 = {'color': 'green', 'points': 5}  # 标准格式 键 : 值
print(alien_0['color'])
print(alien_0['points'])
print(alien_0)
alien_0['x_position'] = 0    #添加键值
alien_0['y_position'] = 25
print(alien_0)
alien_0['x_position'] = 15   #修改字典中的值
print(alien_0)
del alien_0['points']        #删除键值
print(alien_0)
favorite_languages = {       #多行定义字典
    'jen': 'python',
    'sarah': 'c',
    'edward': 'ruby',
    'phil': 'python',
    }
print(favorite_languages) 
#遍历字典所有的键值
for key, value in favorite_languages.items(): #items返回键值对列表
    print("nKey: " + key)
    print("Value: " + value)

for name in favorite_languages.keys():  #遍历字典所有的键，可取消.keys()
    print("n"+name.title()+"n")

friends = ['phil', 'sarah']
for name in favorite_languages.keys():  #使用键访问相关的值
    print(name.title())
    if name in friends:
        print(" Hi " + name.title() +
            ", I see your favorite language is " +
            favorite_languages[name].title() + "!")
#遍历字典所有的值
for language in set(favorite_languages.values()):  #set()可取消相同的值
    print("n"+language.title())


##字典列表
print("nnnn")
# 创建一个用于存储外星人的空列表
aliens = []
# 创建30个绿色的外星人
for alien_number in range (0,30):
    new_alien = {'color': 'green', 'points': 5, 'speed': 'slow'}
    aliens.append(new_alien)
    
for alien in aliens[0:3]:
    if alien['color'] == 'green':
        alien['color'] = 'yellow'
        alien['speed'] = 'medium'
        alien['points'] = 10
# 显示前五个外星人
for alien in aliens[0:5]:
    print(alien)
print("...")
# 显示创建了多少个外星人
print("Total number of aliens: " + str(len(aliens)))

#在字典中存储列表
favorite_languages = {
    'jen': ['python', 'ruby'],
    'sarah': ['c'],
    'edward': ['ruby', 'go'],
    'phil': ['python', 'haskell'],
    }
for name, languages in favorite_languages.items():
    print("n" + name.title() + "'s favorite languages are:")
    for language in languages:
        print("t" + language.title())
        
#字典中嵌套字典
print("字典中嵌套字典")
users = {
    'aeinstein': {
        'first': 'albert',
        'last': 'einstein',
        'location': 'princeton',
        },
    'mcurie': {
        'first': 'marie',
        'last': 'curie',
        'location': 'paris',
        },
    }
for username, user_info in users.items():
    print("nUsername: " + username)
    full_name = user_info['first'] + " " + user_info['last']
    location = user_info['location']
    print("tFull name: " + full_name.title())
    print("tLocation: " + location.title())