006、字典、元組的基本使用和方法
阿新 • • 發佈:2021-07-25
1、字典
key相同,則會覆蓋前面的值 ; 查詢,取值時,students['gender'] 無該 key 則會報錯 ; 查詢,取值時,students.get('gender') 無該 key,返回None ;# key相同,則會覆蓋前面的值; students_1 = {'name': 'sky', 'age': 18, 'height': 170, 'age': 25} print(students_1) # 獲取字典的值 students_2 = {'name': 'sky', 'age': 18, 'height': 170} print(students_2['View Codeage']) # print(students['gender']) # 無該key,報錯:KeyError: 'gender' print(students_2.get('name')) print(students_2.get('gender')) # 無該key,返回None
執行結果如下:
D:\SkyWorkSpace\WorkSpace\Pytest\Temp\day06\venv\Scripts\python.exe D:/SkyWorkSpace/WorkSpace/Pytest/Temp/day06/gggg/demo.py {'name': 'View Code 新增-修改 如果key存在,則修改值;如果key不存在,則新增值 ; 可以新增的值: 字典、列表、元組 等 ; key:一般是字串 ;sky', 'age': 25, 'height': 170} 18 sky None Process finished with exit code 0
students_3 = {'name': 'sky', 'age': 18, 'height': 170} print(students_3) students_3['weight'] = 75.3 print(students_3) students_3['nameView Code'] = 'Tony' print(students_3) students_3['score'] = {'語文': 87, '數學': 78, '英語': 90} print(students_3)
執行結果如下:
D:\SkyWorkSpace\WorkSpace\Pytest\Temp\day06\venv\Scripts\python.exe D:/SkyWorkSpace/WorkSpace/Pytest/Temp/day06/gggg/demo.py {'name': 'sky', 'age': 18, 'height': 170} {'name': 'sky', 'age': 18, 'height': 170, 'weight': 75.3} {'name': 'Tony', 'age': 18, 'height': 170, 'weight': 75.3} {'name': 'Tony', 'age': 18, 'height': 170, 'weight': 75.3, 'score': {'語文': 87, '數學': 78, '英語': 90}} Process finished with exit code 0View Code
刪除
students_1.pop('age') # 刪除指定鍵值對,必須要傳一個key,否則會報錯;
del students_1['height'] # 用del粗暴的回收 ;
print(students_1.popitem()) # 返回並刪除字典中的最後一對鍵和值;
students_1.clear() # 清空字典;
students_1 = {'name': 'sky', 'age': 18, 'height': 170, 'weight': 65, 'hobby': '音樂', 'phone': '榮耀'} print(students_1) # students_1.pop() # 報錯,無該方法,與列表有點不一樣 students_1.pop('age') # 刪除指定鍵值對 print(students_1) del students_1['height'] # 用del粗暴的回收 print(students_1) print(students_1.popitem()) # 返回並刪除字典中的最後一對鍵和值。 print(students_1) students_1.clear() # 清空字典 print(students_1)View Code
執行結果如下:
D:\SkyWorkSpace\WorkSpace\Pytest\Temp\day06\venv\Scripts\python.exe D:/SkyWorkSpace/WorkSpace/Pytest/Temp/day06/gggg/test_2.py {'name': 'sky', 'age': 18, 'height': 170, 'weight': 65, 'hobby': '音樂', 'phone': '榮耀'} {'name': 'sky', 'height': 170, 'weight': 65, 'hobby': '音樂', 'phone': '榮耀'} {'name': 'sky', 'weight': 65, 'hobby': '音樂', 'phone': '榮耀'} ('phone', '榮耀') {'name': 'sky', 'weight': 65, 'hobby': '音樂'} {} Process finished with exit code 0View Code