python_class21

#!/usr/bin/env python
# -*- coding: utf-8 -*-
"""
@version: 3.5
@author: morgana
@license: Apache Licence 
@contact: vipmorgana@gmail.com
@site: 
@software: PyCharm
@file: notes.py
@time: 2017/6/19 上午8:51
"""

# 1.yield的表达式形成的应用
# 2.面向过程编程：grep -rl ‘root‘ /etc
# 3.递归
# 4.内置函数
#
# 三元表达式：res=True if 1>2 else False
# 列表解析：[i for i in range(10) if i>5]
# 生成器表达式：（i for i in range(10) if i>5）
# 生成器：函数函数内部有yield关键字，那函数执行的结果就是生成器


# def init(func):
#     def warpper(*args,**kwargs):
#         g=func(*args,**kwargs)
#         next(g)
#         return g
#     return warpper
#
# @init
# def foo():
#     print(‘starting‘)
#     while True:
#         x=yield
#         print(‘value: ‘,x)

#send的效果
#1.先从为暂停位置的那个yield传一个值，然后yield会把值赋值x
#2:与next的功能一样


# g=foo()
# print(g)
# next(g)
# print(‘=‘*30)
# print(g.send(1))
# print(‘=‘*30)
# print(g.send(2))
# print(g.send(3))
# print(g.send(3))

#


# @init
# def eater(name):
#     print(‘%s read to eat ‘ %name)
#     food_list=[]
#     while True:
#         food=yield food_list
#         food_list.append(food)
#         print("%s start to eat %s" %(name,food))
#
#
#
# e=eater(‘alex‘)
# e.send("shit")
# e.send("dog shit")

#
# def init(func):
#     def warpper(*args,**kwargs):
#         g=func(*args,**kwargs)
#         next(g)
#         return g
#     return warpper
#
#
# @init
# def eater(name):
#     print("%s eat " %(name))
#     food_list=[]
#     while True:
#         food=yield food_list
#         food_list.append(food)
#         print("%s eat %s" %(name,food))
#
#
# def make_shit(people,n):
#     for i in range(n):
#         people.send("shit %s" %i)
#
# e=eater("alex")
# make_shit(e,5)


#1.找到文件
#2.把文件找到 绝对路径 send(）-》
#3.遍历文件内容
#判断

import os
def init(func):
    def warpper(*args,**kwargs):
        g=func(*args,**kwargs)
        next(g)
        return g
    return warpper



# 阶段一：递归找文件绝对路径，把路径发给阶段二
def search(target, start_path):
    ‘serch file abpath‘
    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)
            file_path = ‘%s%s‘ % (par_dir, file)
            #print(file_path)
            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
@init
def opener(target):
    ‘get file obj open(filepath)‘
    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):
    #  ‘cat file‘
    while True:
        file_path, f = yield
        for line in f:

                target.send((file_path,line))


# 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):
    while True:
        file_path, line = yield
        if pattern in line:
            target.send(file_path)


# 阶段五：收到文件名打印结果
@init
def printer():
    # ‘print function‘
    while True:
        filename = yield
        print(filename)


start_path =‘/Users/shuanggai/PycharmProjects/git/python/20170619_yield_recursion/homework/‘
search(opener(cat(grep(printer(),‘root‘))),start_path)