# study python 2019-02-11# 使用字典 在python中 字典是一系列键值对，每个键都与一个值相互关联# 存储一些外星人 颜色和点数
alien_0 = {'color':'red','points':5}
print(alien_0['color'])# 访问字典里面的值
print(alien_0['points'])# 往字典里面添加值
alien_0["mode"] = 'primary'
print(alien_0)# 创建一个空字典
alien_1 = {}# 字典增加值
alien_1['color'] = 'pink'
alien_1['point'] = 20
alien_1['mode'] = 'nightmare'print(alien_1)# 修改字典里面的值
alien_1['point'] = 100
print(alien_1)# 删除字典里面的值, 删除时就永远消失了
del alien_1['point']
print(alien_1)# 由类似对象组成的字典
favorite_languages = {'song' : 'python','sarah' : 'java','phil' : 'javascript'
}favorite_languages['phil'] = 'java'
print(favorite_languages)# 遍历字典
user_0 = {'username' : 'zhangsan','age' : '20','address' : '上海'
}print("遍历所有键值对")
for key, value in user_0.items():print('key: ' + key)print('value: ' + value)print("============遍历所有键值对=======================")
for k, v in user_0.items():print('key: ' + k)print('value: ' + v)print("=============遍历字典中所有的键======================")
# 遍历字典中所有的键friends = ['username']
for name in user_0.keys():if name in friends:print(" Hi " + name.title())else:print("not exist")print("===================================")friends = ['username']
for name in user_0.keys():if name not in friends:print(" Hi " + name.title())else:print("you are exist: " + name)print("============按顺序遍历所有的键=======================")
# 按顺序遍历所有的键
for name in sorted(user_0.keys()):print('name: ' + name)print("===================================")
# 按顺序遍历所有的值
for value in sorted(user_0.values()):print('value: ' + value)print("===============可以使用set集合====================")
# 提取字典里面的值 可能包含重复项，为了剔除重复项，可以使用set集合，使得每个元素都是独一无二的
languages = {'tim': 'java','jack': 'python','json': 'javascript','lucy': 'java','tom': 'c',
}for value in set(languages.values()):print('value: ' + value)
print("==============遍历列表=====================")# 嵌套'''有时候需要将一系列字典存储在列表中，或者将列表作为值存储在字典中，这称为嵌套
'''alien_0 = {'color':'pink','point':5}
alien_1 = {'color':'green','point':15}
alien_2 = {'color':'red','point':10}# 将三个字典放入一个列表中
aliens = [alien_0,alien_1,alien_2]# 遍历列表
for alien in aliens:print(alien)
print("===================================")# 创建一个空的列表
aliens = []for alien in range(10):alien = {'color':'pink','point':5}aliens.append(alien)
print(alien)print("==================显示前三个=================")
# 显示前三个
for k in aliens[:3]:print(k)print("=================显示所有==================")
# 显示所有
for k in aliens:print(k)# 显示列表长度
print(len(aliens))# 列表中存储字典
pizza = {'crust' : 'thick','toppings' : ['mushrooms','extra cheese']
}
print("=================列表中存储字典=================")
for topping in pizza['toppings']:print(topping)# 字典里面存储列表
favorite_languages = {'song' : ['java','c'],'lv' : ['java','c++'],'jun': ['javascript', 'c++'],
}
print("=================字典里面存储列表=================")
for name, language in favorite_languages.items():print(name + " love course are: ")for lang in language:print(lang)# 字典里面存储字典
print("=================字典里面存储字典=================")
user = {'info' : {'age' : 20,'password' : '123456','address' : '上海',},'love' : {'age': 30,'password': '456','address': '上海',}
}for info, love in user.items():print(user[info]['age'])for info, love in user.items():print(love['age'])