Python学习笔记四:列表(二)
1.修改、添加、删除列表元素
(1)修改
通过索引,修改你想要修改的位置对应的元素
1. names=['Li hua','Kang Kang','Han Mei Mei']
2. names[0]='Zhang San'
3. print(names)
4. ['Zhang San','Kang Kang','Han Mei Mei']
(2)添加
在末尾添加
1. names=['Li hua','Kang Kang','Han Mei Mei']
2. names.append('Zhang San')
3. print(names)
4. ['Li hua','Kang Kang','Han Mei Mei','Zhang San']
在列表任意位置插入元素
1. names=['Li hua','Kang Kang','Han Mei Mei']
2. names.insert(1,'Zhang San')
3. print(names)
4. ['Li hua','Zhang San','Kang Kang','Han Mei Mei']
(3)删除
1.若知道位置
1. names= ['Li hua','Kang Kang','Han Mei Mei']
2. del names[0]
3. print(names)
4.['Kang Kang','Han Mei Mei']
2.使用pop()删除,相当于弹出末尾元素或者任何位置的元素,并可以接着使用这个元素
1. names= ['Li hua','Kang Kang','Han Mei Mei']
2. name_1=names.pop()
3. print(names)
4. print(name_1)
5. ['Li hua','Kang Kang']
6. Han Mei Mei
#这样将Han Mei Mei存储在name_1中了
1. names= ['Li hua','Kang Kang','Han Mei Mei']
2. name_2=names.pop(1)
3. print(names)
4. print(name_2)
5. ['Li hua','Han Mei Mei']
6. Kang Kang
3.使用remove(),对确定的值进行删除
1. names= ['Li hua','Kang Kang','Han Mei Mei']
2. names.remove('Li hua')
3. print(names)
4. ['Kang Kang','Han Mei Mei']
2.组织列表
(1)排序
1.临时排序,使用sorted(),按字母排序
1. letters=['a','c','d','b']
2. print(letters.sorted())
3. print(letters)
4. ['a','b','c','d']
5. ['a','c','d','b']
#这样只是临时性的
1.1反序,sorted(reverse=True),按字母顺序相反
1. letters=['a','c','d','b']
2. letters.sorted(reverse=True)
3. print(letters)
4. ['d','c','b','a']
#这也是临时性的
2.永久性排序,使用sort(),
1. letters=['a','c','d','b']
2. print(letters.sort())
3. print(letters)
4. ['a','b','c','d']
5. ['a','b','c','d']
2.1反序,sort(reverse=True)
1. letters=['a','c','d','b']
2. letters.sort(reverse=True)
3. print(letters)
4. ['d','c','b','a']
#永久性的
(2)倒着打印列表
使用reverse()
1. letters=['a','c','d','b']
2. letters.reverse()
3. print(letters)
4. ['b','d','c','a']
(3)获取列表长度
1. letters=['a','c','d','b']
2. print(len(letters))
3. 4