python - lambda 函数使用

# if we need it only once and it's quite simple
def make_incrementor(n): return lambda x: x + n
f = make_incrementor(2)
print f(3)

# filter, map, reduce
foo = [2, 18, 9, 22, 17, 24, 8, 12, 27]
print filter(lambda x: x % 3 == 0, foo)
print map(lambda x: x * 2 + 10, foo)
print reduce(lambda x, y: x + y, foo)

nums = range(2, 50)
for i in range(2, 8):
    nums = filter(lambda x: x == i or x % i, nums)
print nums

print map(lambda word: len(word), "it is raining cats and dogs".split())

import commands
print map(lambda x: x.split()[2],commands.getoutput('mount -v').splitlines())
# or
lines = commands.getoutput('mount -v').splitlines()
points = map(lambda line: line.split()[2], lines)
print points