Python__面向过程编程

面向过程：核心是面向过程，过程即解决问题的步骤，基于面向过程去设计程序，就像是在设计流水线

#优点：程序结构清晰，可以把复杂的问题简单化，流程化
#缺点：可扩展性差，一条流水线只是用来解决一个问题
os模块功能展示：

#Author wangmengzhu
#装饰器
def init(func):
    def wrapper(*args,**kwargs):
        g = func(*args,**kwargs)
        next(g)
        return g
    return wrapper
#第一阶段，找到所有文件的绝对路径
import os
@init
def search(target):
    while True:
        filepath = yield
        g = os.walk(filepath)
        for dirpath,_,files in g:
            for file in files:
                abspath = r'%s\%s'%(dirpath,file)
                target.send(abspath)


#第二阶段，打开文件
@init
def opener(target):
    while True:
        abspath = yield
        with open(abspath) as f:
            target.send((abspath,f))


#第三阶段，循环读出每一行的内容
@init
def cat(target):
    while True:
        abspath,f = yield
        for line in f:
            res = target.send((line,abspath))
            if res:
                break

#第四阶段，过滤
@init
def grep(pattern,target):
    tag = False
    while True:
        line,abspath = yield tag
        tag = False
        if pattern in line:
            target.send(abspath)
            tag = True
#第五阶段
@init
def printer():
    while True:
        abspath = yield
        print(abspath)
g = search(opener(cat(grep('error',printer()))))
g.send(r'C:UserswangmengzhuPycharmProjectsMZa')