map，filter,reduce运用

#author:徐征
    #=====================作业一
#用map来处理字符串列表啊,把列表中所有人都变成sb,比方lin_sb
name=['lin','hai','feng']
m=map(lambda name:name+"_NB",name)
print(list(m))
'''['lin_NB', 'hai_NB', 'feng_NB']'''
#用map来处理下述l，然后用list得到一个新的列表，列表中每个人的名字都是sb结尾
l=[{'name':'egon'},{'name':'d'}]
print(list(map(lambda name:name["name"]+"_NB", l)))
'''['egon_NB', 'd_NB']'''
#=====================作业二
#用filter来处理,得到股票价格大于20的股票名字
shares={
    'IBM':36.6,
    'Lenovo':23.2,
    'oldboy':21.2,
    'ocean':10.2,
}
f=filter(lambda price:shares[price]>20,shares)
for i in f:
    print(i)
''' IBM
    Lenovo
    oldboy
'''

# =====================作业三
#如下，每个小字典的name对应股票名字，shares对应多少股，price对应股票的价格
portfolio = [
    {'name': 'IBM', 'shares': 100, 'price': 91.1},
    {'name': 'AAPL', 'shares': 50, 'price': 543.22},
    {'name': 'FB', 'shares': 200, 'price': 21.09},
    {'name': 'HPQ', 'shares': 35, 'price': 31.75},
    {'name': 'YHOO', 'shares': 45, 'price': 16.35},
    {'name': 'ACME', 'shares': 75, 'price': 115.65}
]
#1:map来得出一个包含数字的迭代器，数字指的是：购买每支股票的总价格
z=map(lambda total_prices:{total_prices["name"]:total_prices["shares"]*total_prices["price"]},portfolio)
for i in z:
    print(i)
''' {'IBM': 9110.0}
    {'AAPL': 27161.0}
    {'FB': 4218.0}
    {'HPQ': 1111.25}
    {'YHOO': 735.7500000000001}
    {'ACME': 8673.75}
'''
#2:基于1的结果，用reduce来计算，购买这些股票总共花了多少钱
from functools import reduce
z=map(lambda total_price:total_price["shares"]*total_price["price"],portfolio)
print(reduce(lambda x,y:x+y,z))
'''51009.75'''
#3：用filter过滤出，单价大于100的股票有哪些
f=filter(lambda price:price["price"] > 100,portfolio)
for i in f:
    print(i)
''' {'name': 'AAPL', 'shares': 50, 'price': 543.22}
    {'name': 'ACME', 'shares': 75, 'price': 115.65}
'''