在python中利用pipe实现管道

参考书：张颖，赖勇浩，编写高质量代码：改善python程序的91个建议

所有代码在python3.6（win10）上测试通过。

例子：

from pipe import *
import operator
from functools import reduce

# basic example
y = range(1,6) | where(lambda x: x % 2) | tail(2) | select(lambda x: x * x) | add
print(f"pipe_result: {y}")
z = reduce(operator.add, [i * i for i in range(3, 6, 2)])
print(f"standard_realization: {z}")


# fibonacci example
def fib():
    a, b = 0, 1
    while True:
        yield a
        a, b = b, a + b
p = fib() | take_while(lambda x: x < 4000000) \
    | where(lambda x: x % 2 == 0)  | add
print(f"fibonacci even result: {p}")

输出结果：

pipe_result: 34
standard_realization: 34
fibonacci even result: 4613732