一、lambda函數的語法
lambda語句中，冒號前是參數，可以有0個或多個，用逗號隔開，冒號右邊是返回值。lambda語句構建的其實是一個函數對象。
1》無參數：
f = lambda:'Hello python lambda' f() #'Hello python lambda'
2》有參數，無默認值
f = lambda x,y: x*y f(6,7) #42
3》有參數，有默認值
f = lambda x=5, y=8: x*y f() #40 f(5,6) #30
4》和map, reduce, filter連用
foo = [2, 18, 9, 22, 17, 24, 8, 12, 27] print filter(lambda x: x % 3 == 0, foo)#python 2.x list( filter(lambda x: x % 3 == 0, foo) )#python 3.x #[18, 9, 24, 12, 27] print map(lambda x: x * 2 + 10, foo)#python 2.x list( map(lambda x: x * 2 + 10, foo) )#python 3.x #[14, 46, 28, 54, 44, 58, 26, 34, 64] from functools import reduce#python 3.x need import reduce reduce(lambda x, y: x + y, foo) #139