匿名函数

#匿名函数关键字：lambda
def add(x,y):
    return x+y
#匿名函数
add = lambda x,y:x+y
print(add(1,2))

#求value值对应最大的key值
dic={‘k1‘:10,‘k2‘:100,‘k3‘:30}
def func(key):
    return dic[key]
print(max(dic,key=func))   #根据返回值判断最大值，返回值最大的那个参数是结果
print(max(dic,key=lambda key:dic[key]))
max([1,2,3,4,5,-6,-7],key=abs)

ret = map(abs,[-1,2,-3,4])
for i in ret:
    print(i)

def func(x):
    return x**2
ret = map(func,[-1,2,-3,4])
for i in ret:
    print(i)

ret = map(lambda x:x**2,[-1,2,-3,4])


def func(x):
    return x>10

res = filter(func,[5,8,11,9,15])
for i in res:
    print(i)


# min max filter map sorted —— lambda

#面试题1
d = lambda p:p*2
t = lambda p:p*3
x = 2
x = d(x) #x = 4
x = t(x) #x = 12
x = d(x) #x = 24
print(x)

#面试题2
ret = zip(((‘a‘),(‘b‘)),((‘c‘),(‘d‘)))
ret = map(lambda t:{t[0]:t[1]},ret)
print(list(ret))

#现有两元组((‘a‘),(‘b‘)),((‘c‘),(‘d‘)),
# 请使用python中匿名函数生成列表[{‘a‘:‘c‘},{‘b‘:‘d‘}]

# max min sorted filter map
# 匿名函数 == 内置函数
# zip  map
ret = zip(((‘a‘),(‘b‘)),((‘c‘),(‘d‘)))
res = map(lambda tup:{tup[0]:tup[1]},ret)
print(list(res))

#面试题3
def multipliers():
    return [lambda x:i*x for i in range(4)]
print([m(2) for m in multipliers()])