Python學習之路-字典dict常用方法
阿新 • • 發佈:2018-02-21
round 存在 set get 輸出 查詢 val 沒有 span
字典特性:
- dict無序
- key唯一,天生去重
創建字典:
way1:小心列表坑
1 __author__ = "KuanKuan" 2 d = dict.fromkeys([1, 2, 3], ["name", "age"]) 3 print("字典:", d) 4 5 d[1][0] = "mmph好坑" 6 print("修改後:",d) 7 """ 8 輸出: 9 字典: {1: [‘name‘, ‘age‘], 2: [‘name‘, ‘age‘], 3: [‘name‘, ‘age‘]} 10 修改後: {1: [‘mmph好坑‘, ‘age‘], 2: [‘mmph好坑‘, ‘age‘], 3: [‘mmph好坑‘, ‘age‘]}11 12 """
way2:
1 info = {"teacher1":"蒼井空", 2 "teacher2":"京香", 3 "teacher3":"波多野結衣", 4 "teacher4":"小澤瑪利亞" 5 } 6 print("你懂得:",info) 7 """ 8 輸出: 9 你懂得: {‘teacher1‘: ‘蒼井空‘, ‘teacher2‘: ‘京香‘, ‘teacher3‘: ‘波多野結衣‘, ‘teacher4‘: ‘小澤瑪利亞‘} 10 """
字典無序輸出
查詢
(info["teacher1"])#如果不存在會報錯 print(info.get("teacher5"))#推薦用這種方式如果key不存在則返回None print("teacher1" in info)#如果存在返回True print("查詢字典的keys:",info.keys())#查詢字典的keys print("查詢字典的values:",info.values())#查詢字典的values print(info.items()) """ 蒼井空 None True 查詢字典的keys: dict_keys([‘teacher1‘, ‘teacher2‘, ‘teacher3‘, ‘teacher4‘]) 查詢字典的values: dict_values([‘蒼井空‘, ‘京香‘, ‘波多野結衣‘, ‘小澤瑪利亞‘]) dict_items([(‘teacher1‘, ‘蒼井空‘), (‘teacher2‘, ‘京香‘), (‘teacher3‘, ‘波多野結衣‘), (‘teacher4‘, ‘小澤瑪利亞‘)])"""
修改
1 info["teacher1"] = "天海翼" 2 print("修改後:",info) 3 #修改後: {‘teacher1‘: ‘天海翼‘, ‘teacher2‘: ‘京香‘, ‘teacher3‘: ‘波多野結衣‘, ‘teacher4‘: ‘小澤瑪利亞‘}
增加
1 info["teacher1"] = "天海翼" 2 print("修改後:",info) 3 #修改後: {‘teacher1‘: ‘天海翼‘, ‘teacher2‘: ‘京香‘, ‘teacher3‘: ‘波多野結衣‘, ‘teacher4‘: ‘小澤瑪利亞‘} 4 info["teacher5"] = "上原瑞惠"#沒有則自動創立 5 print("增加後的字典:",info) 6 info.setdefault("teacher1","櫻井莉亞")#存在則不會被修改 7 info.setdefault("teacher6","櫻井莉亞") 8 print(info) 9 b = {"teacher1":"蒼井空", 10 "teacher7":"桃谷繪裏香" 11 } 12 info.update(b) 13 print("修改後的:",info) 14 """ 15 修改後: {‘teacher1‘: ‘天海翼‘, ‘teacher2‘: ‘京香‘, ‘teacher3‘: ‘波多野結衣‘, ‘teacher4‘: ‘小澤瑪利亞‘} 16 增加後的字典: {‘teacher1‘: ‘天海翼‘, ‘teacher2‘: ‘京香‘, ‘teacher3‘: ‘波多野結衣‘, ‘teacher4‘: ‘小澤瑪利亞‘, ‘teacher5‘: ‘上原瑞惠‘} 17 {‘teacher1‘: ‘天海翼‘, ‘teacher2‘: ‘京香‘, ‘teacher3‘: ‘波多野結衣‘, ‘teacher4‘: ‘小澤瑪利亞‘, ‘teacher5‘: ‘上原瑞惠‘, ‘teacher6‘: ‘櫻井莉亞‘} 18 修改後的: {‘teacher1‘: ‘蒼井空‘, ‘teacher2‘: ‘京香‘, ‘teacher3‘: ‘波多野結衣‘, ‘teacher4‘: ‘小澤瑪利亞‘, ‘teacher5‘: ‘上原瑞惠‘, ‘teacher6‘: ‘櫻井莉亞‘, ‘teacher7‘: ‘桃谷繪裏香‘} 19 """
刪除
1 del info["teacher1"] 2 print("刪除後的:",info) 3 info.pop("teacher2") 4 print("刪除後的2:",info) 5 info.popitem() 6 print("隨機刪除後的:",info) 7 """ 8 刪除後的: {‘teacher2‘: ‘京香‘, ‘teacher3‘: ‘波多野結衣‘, ‘teacher4‘: ‘小澤瑪利亞‘, ‘teacher5‘: ‘上原瑞惠‘, ‘teacher6‘: ‘櫻井莉亞‘, ‘teacher7‘: ‘桃谷繪裏香‘} 9 刪除後的2: {‘teacher3‘: ‘波多野結衣‘, ‘teacher4‘: ‘小澤瑪利亞‘, ‘teacher5‘: ‘上原瑞惠‘, ‘teacher6‘: ‘櫻井莉亞‘, ‘teacher7‘: ‘桃谷繪裏香‘} 10 隨機刪除後的: {‘teacher3‘: ‘波多野結衣‘, ‘teacher4‘: ‘小澤瑪利亞‘, ‘teacher5‘: ‘上原瑞惠‘, ‘teacher6‘: ‘櫻井莉亞‘} 11 12 """
遍歷
for i in info: print(i,info[i]) print("*"*50) for key,value in info.items():#先轉列表,在遍歷,如果字典過大,會變慢 print(key,value) """ teacher3 波多野結衣 teacher4 小澤瑪利亞 teacher5 上原瑞惠 teacher6 櫻井莉亞 ************************************************** teacher3 波多野結衣 teacher4 小澤瑪利亞 teacher5 上原瑞惠 teacher6 櫻井莉亞 """
清空
1 info.clear() 2 print("清空後的:",info) 3 #清空後的: {}
Python學習之路-字典dict常用方法