匿名函数和map()

 1 num=[1,2,5,9,8]
 2 def add(x):#lambda x:x+1
 3     return x+1
 4 def sub(x):#lambda x:x-1
 5     return x-1
 6 def squ(x):#lambda x:x**2
 7     return x**2
 8 def map_test(func,x):
 9     array = []
10     for i in num:
11         res = func(i)
12         array.append(res)
13     return array
14 # res = map_test(add,num)
15 print(map_test(lambda x:x+1,num))
16 print(map_test(lambda x:x-1,num))
17 print(map_test(lambda x:x**2,num))
运行结果:
[2, 3, 6, 10, 9]
[0, 1, 4, 8, 7]
[1, 4, 25, 81, 64]

Process finished with exit code 0
 1 num=[1,2,5,8,15]
 2 def map_test(func,x):
 3     array=[]
 4     for i in x:
 5         res=func(i)
 6         array.append(res)
 7     return array
 8 ret = map_test(lambda x:x+1,num)
 9 ret2=map_test(lambda x:x**2,num)
10 print(ret)
11 print(ret2)
运行结果:
[2, 3, 6, 9, 16]
[1, 4, 25, 64, 225]

Process finished with exit code 0

 

map()内置函数:

num=[1,2,5,8,15]
res = map(lambda x:x+1,num)#map函数的用法:map(处理方法,可迭代对象)
print(res)
print(list(res))
运行结果:
<map object at 0x01761930> # 地址值
[2, 3, 6, 9, 16]

Process finished with exit code 0

 

str='dajdkaa'
map(lambda x:x.upper(),atr)#转换大小写
list(map(lambda x:x.upper(),atr))#转换为列表
print(map(lambda x:x.upper(),atr))#输出

  

 

  

 

posted @ 2018-05-21 22:24  容颜-gl  阅读(597)  评论(0编辑  收藏  举报