python3—列表

列表是什么

name = ["jim", "lilei", "lucy"]     #方括号表示，逗号分隔
print(name)
print(name[0])
print(name[0].title())

输出：

['jim', 'lilei', 'lucy']
jim
Jim

name = ["jim", "lilei", "lucy"]

print(name[0], name[1], name[2])
print(name[-1], name[-2], name[-3])   #-1索引表示最后一个元素

输出:

jim lilei lucy
lucy lilei jim

name = ["jim", "lilei", "lucy"]
name[0] = 'lily'  #修改第一个元素
print(name)

#添加元素
name.append('xiaoming')   #在末尾添加
print(name)
name.insert(1,'ouyangfeng')   #在name[1]处添加，原来的name[1]以及以后的后移
print(name)

del name[1]  #删除name[1]，以后不用name[1]了
print(name)

delete_end = name.pop()
print(delete_end, name)

delete_name = name.pop(1)  #删除name[1]，以后还可以用
print("delete_name: ",delete_name)
print(name)

name.remove('lucy')  #删除lucy
print(name)

输出：

['lily', 'lilei', 'lucy']
['lily', 'lilei', 'lucy', 'xiaoming']
['lily', 'ouyangfeng', 'lilei', 'lucy', 'xiaoming']
['lily', 'lilei', 'lucy', 'xiaoming']
xiaoming ['lily', 'lilei', 'lucy']
delete_name:  lilei
['lily', 'lucy']
['lily']

永久排序：

cars =['dazhong','Baoma','aodi','qq','Qirui']
cars.sort() #按字母从小到大
print(cars)

cars.sort(reverse=True)  #按字母从大到小
print(cars)

output:

['Baoma', 'Qirui', 'aodi', 'dazhong', 'qq']
['qq', 'dazhong', 'aodi', 'Qirui', 'Baoma']

临时排序：

cars =['dazhong','Baoma','aodi','qq','Qirui']
tmp_sort = sorted(cars)
print("tmp_sort:",tmp_sort)
print("origianl:",cars)
print("large->small:",sorted(cars,reverse=True))
print("origianl:",cars)

output:

tmp_sort: ['Baoma', 'Qirui', 'aodi', 'dazhong', 'qq']
origianl: ['dazhong', 'Baoma', 'aodi', 'qq', 'Qirui']
large->small: ['qq', 'dazhong', 'aodi', 'Qirui', 'Baoma']
origianl: ['dazhong', 'Baoma', 'aodi', 'qq', 'Qirui']

反转：

cars =['dazhong','Baoma','aodi','qq','Qirui']
print(cars)

cars.reverse()
print(cars)

cars.reverse()
print("recover: ", cars)

output:

['dazhong', 'Baoma', 'aodi', 'qq', 'Qirui']
['Qirui', 'qq', 'aodi', 'Baoma', 'dazhong']
recover:  ['dazhong', 'Baoma', 'aodi', 'qq', 'Qirui']

cars =['dazhong','Baoma','aodi','qq','Qirui']
length = len(cars)
print(length)

output:

5