定義一個字典
{key1:value1,key2:value2}
info = {"name":"laowang","old":18}
添加元素
info = {"name":"laowang","old":18}
info["old"] = 18 #info = {"name":"laowang","old":18}
修改元素
info = {"name":"laowang","old":18}
info["old"] = 20 #{"name":"laowang","old":20}
刪除元素
info = {"name":"laowang","old":18}
del info["old"] #{"name":"laowang"}
查詢元素
info = {"name":"laowang","old":18}
info.get("name") #laowang
info.get("qq") # 空
info["qq"] #拋出異常
常用屬性
len 鍵值對的個數(shù)
info = {"name":"laowang","old":18}
info.len() # 打印信息2
keys 字典中所有的鍵列表
info = {"name":"laowang","old":18}
info.keys() # 打印信息["name","old"]
values 字典中所有的值列表
info = {"name":"laowang","old":18}
info.values() # 打印信息["laowang",18]
items 字典中所有的鍵值元組列表
info = {"name":"laowang","old":18}
info.items() # 打印信息[("name","laowang"),("old",18)]
字典中的key不能是列表類型固额，可以是字符串帮碰、數(shù)字驾孔、元組
