list 操作

animals = ["aardvark", "badger", "duck", "emu", "fennec fox"]

print(animals[1:3])    # print "badger" and "duck"

duck_index = animals.index("duck")   # Use index() to find "duck"

animals.insert(2,"cobra") #insert "cobra" at index 2,which move everything down by 1. #插入

animals.remove("duck")  #删除"duck"

# 遍历list

my_list = [1,9,3,8,5,7]
for number in my_list:  
    print(number * 2)    # print a number equal to 2 * for every list item

for index, item in enumerate(my_list):
    print index , item  # 得到 index（从 0 开始） 和 my_list 的内容

# 排序

start_list = [5, 3, 1, 2, 4]
str = ["bb","aa","AA","ac"]
start_list.sort()
str.sort()
print(square_list)  #输出 1，2，3，4，5
print(str)  #输出 "AA","aa","ac","bb"


#删除
list = [1,2,3,4,5]
list.remove(value)  # 从list中删除value
list.pop(index)     # 从list中删除下标为index的数(从0开始)
del(list[index])    # 从list中删除下标为index的数(从0开始)

#lis相加
a = [1,2,3]
b = [4,5,6]
a + b  # 得到 [1,2,3,4,5,6]

#同时比较多个list
list_a = [3, 9, 17, 15, 19]
list_b = [2, 4, 8, 10, 30, 40, 50, 60, 70, 80, 90]

for a, b in zip(list_a, list_b):
    # 输出较大的数
    if a > b:
        print a
    else:
        print(b)
    # 得到 3,9,17,15,30

# list comprehension （满足一定条件）
doubles_by_3 = [x for x in range(0,10) if x % 2 == 0] #得到[0，2,4，6,8]
even_squares = [x ** 2 for x in range(1,11) if x % 2 == 0] #得到[4,16,36,64,100]

#Lambda Syntax （选择满足条件的）
languages = ["HTML", "JavaScript", "Python", "Ruby"]
print filter(lambda str : str == "Python", languages) #输出 "Python" 

#选择某些下标对应的值
print(list[start:end:step]）
#缺省start时默认从零开始，缺省end时默认到最后，缺省step时默认step=1
#当step为正数时，从左到右；step为负数时，从右到左