10-day10-yield的表达式形式

#! /usr/bin/env python
# -*- coding: utf-8 -*-
# __author__ = "w.z"
# Date: 2017/6/19

# send 先传值给yield,再从终端处继续执行...可以通过yield传值，不能第一次直接g.send(2).可以用装饰器，伪装成next一次。

#
def foo():
    print('starting')
    while True:
        x = yield
        print('xx', x)
g = foo()

next(g)

g.send(1)
print(g.send(1)) print会打印返回值
print(g.send(None))


#  加装饰器

def init(func):
    def wrapper():
        g = func()
        next(g)
        return g
    return wrapper


@init
def foo():
    print('starting')
    while True:
        x1 = yield
        print('xx', x1)

x = foo()
x.send(1)
x.send(2)
x.send(3)

# 加装饰器 传入参数


def init(func):
    def wrapper(*args, **kwargs):
        g = func()
        next(g)
        return g
    return wrapper


@init
def foo(*args, **kwargs):
    print('starting')
    while True:
        x1 = yield
        print('xx', x1)

x = foo('alex', 'food1')
next(x)
x.send(1)
x.send(2)
x.send(3)


# 面向过程的编程:grep -rl 'root' /etc
# grep -rl 找出所有文件的绝对路径  os.walk
# start_path = r'C:Userscx2cDesktoppytest'
# search(operer(cat(grep(printer(),'root')))start_path)

import os

def init(func):
    def wrapper(*args, **kwargs):
        g = func(*args, **kwargs)
        next(g)
        return g
    return wrapper

# 第一阶段：递归地找文件绝对路径，发给阶段二


def search(target, start_path):
    g = os.walk(start_path)
    for par_dir, _, files in g:
        for file in files:
            file_path = r'%s\%s' % (par_dir, file)
            target.send(file_path)

# 阶段二收到文件路径，打开文件获取对象，把文件对象发给阶段三


def opener(target):
    while True:
        file_path = yield
        with open(file_path,encoding='utf-8') as f:
            target.send(file_path,f)


@init
def cat(target):
    while True:
        filepath, f =yield
        for line in f:
            target.send(filepath, line)



@init
def grep(target, pattern):
    while True:
        filepath, line = yield
        if pattern in line:
            target.send(filepath)


@init
def printer():
    while True:
        filename = yield
        print(filename)

start_path = r'C:Userscx2cDesktoppytest'
search(opener(cat(grep(printer(), 'root'))), start_path)

要默写的作业

# 作业2 grep -rl 'root' /etc

import os

# 装饰器配合生成器用，对被装饰对象执行一次next(func()) 操作


def init(func):
    def wrapper(*args, **kwargs):
        g = func(*args, **kwargs)
        next(g)
        return g

    return wrapper


# 阶段一：递归地找文件的绝对路径，把路径发给阶段二


@init
def search(target):
    while True:
        start_path = yield
        g = os.walk(start_path)
        for par_dir, _, files in g:
            # print(par_dir,files)
            for file in files:
                file_path = r'%s\%s' % (par_dir, file)
                target.send(file_path)

# 阶段二：收到文件路径，打开文件获取获取对象，把文件对象发给阶段三


@init
def opener(target):
    while True:
        file_path = yield
        with open(file_path, encoding='utf-8') as f:
            target.send((file_path, f))


# 阶段三：收到文件对象，for循环读取文件的每一行内容，把每一行内容发给阶段四

@init
def cat(target):
    while True:
        filepath, f = yield
        for line in f:
            res = target.send((filepath, line))
            if res:
                break


# 阶段四：收到一行内容，判断root是否在这一行中，如果在，则把文件名发给阶段五
@init
def grep(target, pattern):
    tag = False
    while True:
        filepath, line = yield tag  # target.send((filepath,line))
        tag = False
        if pattern in line:
            target.send(filepath)
            tag = True


# 阶段五：收到文件名，打印结果


@init
def printer():
    while True:
        filename = yield
        print(filename)


# start_path1 = r'C:UsersAdministratorPycharmProjectspython5期a'
# start_path2 = r'C:UsersAdministratorPycharmProjectspython5期a'
start_path1 = r'C:Userscx2cDesktoppytest10-day-10'
g = search(opener(cat(grep(printer(), 'root'))))

# print(g)
# g.send(start_path1)
# g.send(start_path2)

g.send(start_path1)

# import os
# print(os.walk(r'C:Userscx2cDesktoppytest'))
# gg = os.walk(r'C:Userscx2cDesktoppytest')    # generator
# for path, _, files in gg:
#     for file in files:
#         print('%s\%s' % (path, file))