Python的数据结构 -- 序列

shoppingList = ['apple','banana','cat','dog','duck']

#Indexing and 'subscription operation'
print('The first item is',shoppingList[0])
print('The second item is',shoppingList[1])
print('the third item is',shoppingList[2])
print('item -1 is',shoppingList[-1])
print('item -2 is',shoppingList[-2])

#Slicing on a list
print('Form the 1 to 3 is',shoppingList[1:3])
print('From the 2 to 4 is',shoppingList[2:4])
print('Form the 1 to -1 is',shoppingList[2:-3])
print('From the start to end is',shoppingList[:])

#Slicing on a String
name='keritafranklin'
print('From the 1 to 3 is',name[1:3])
print('From the 2 to 4 is',name[2:4])
print('From the 1 to -1 is',name[1:-1])
print('From the start to end is',name[:])

#序列的特性：
#1、索引操作符
#2、切片操作符
#  -1指的是最后一个、-2指的是倒数第二个。以此类推
#  如果在某个区间没有元素，则返回[]
#  如果用这样引用[:]，则表示输出所有元素
#  切片时从第一个序列开始，到第二个序列前截止

2015/4/21