函数式编程补充

r = [4, 8, 7, 1]
def cat(array):
    o = []
    for i in r:
        o.append(i**2)
    return o
v = cat(r)
print(v)

r = [4, 8, 7, 1]
def addone(x):
    return x+1
def cat(func,array):  #（func就是运行方法，array就是值）
    o = []
    for i in r:
        a = func(i)
        o.append(a)
    return o
v = cat(addone,cat)
print(v)

print(map_test(lambda x:x**2,num_l)) #不定义函数，直接用匿名函数

#终极版本
def map_test(func,array): #func=lambda x:x+1    arrary=[1,2,10,5,3,7]
    ret=[]
    for i in array:
        res=func(i) #add_one(i)
        ret.append(res)
    return ret

print(map_test(lambda x:x+1,num_l))
res=map(lambda x:x+1,num_l)
print(‘内置函数map，处理结果‘,res)
# for i in res:
#     print(i)
print(list(res))
print(‘传的是有名函数‘,list(map(reduce_one,num_l)))


msg=‘linhaifeng‘
print(list(map(lambda x:x.upper(),msg)))

r = ["sbnm","sbo","sbp","longkuiqi"]
ret = []
for i in r:
    if not i.startswith("sb"):
        ret.append(i)
print(ret)

r = ["sbnm","sbo","sbp","longkuiqi"]
def cat(array):
    ret = []
    for i in array:
        if not i.startswith("sb"):
            ret.append(i)
    return ret
print(cat(r))

r = ["dfssb","fdfsb","esb","longkuiqi"]
def dog(n):
    return n.endswith("sb")

def cat(func,array):
    ret = []
    for i in array:
        if not func(i):
            ret.append(i)
    return ret
v = cat(dog,r)
print(v)

r = ["dfssb","fdfsb","esb","longkuiqi"]

v = list(filter(lambda n:not n.endswith("sb"),r)) #因为默认是返回ture的值，可以用not来得到false的值
print(v)

# from functools import reduce

num = [1,2,3,4,100]
res = 0
for i in num:
    res += i

print(res)

def multi(x,y):  #注意乘法需要两个参数
     return x*y  

def reduce_test(func,array):
    res=array.pop(0)
    for num in array:
        res=func(res,num)
    return res

print(reduce_test(lambda x,y:x*y,num_l))

#处理序列中的每个元素，得到的结果是一个‘列表’，该‘列表’元素个数及位置与原来一样
# map()

#filter遍历序列中的每个元素，判断每个元素得到布尔值，如果是True则留下来

people=[
    {‘name‘:‘alex‘,‘age‘:1000},
    {‘name‘:‘wupei‘,‘age‘:10000},
    {‘name‘:‘yuanhao‘,‘age‘:9000},
    {‘name‘:‘linhaifeng‘,‘age‘:18},
]
print(list(filter(lambda p:p[‘age‘]<=18,people)))


#reduce:处理一个序列，然后把序列进行合并操作
from functools import reduce
print(reduce(lambda x,y:x+y,range(100),100))
print(reduce(lambda x,y:x+y,range(1,101)))