Python - 並行処理とネットワーク(Redis データ構造サーバー、中間媒体、リスト、キュー)

入門 Python 3
原著

開発環境

• OS X El Capitan - Apple (OS)
• Emacs (Text Editor)
• Python 3.5 (プログラミング言語)

入門 Python 3 (Bill Lubanovic (著)、 斎藤 康毅(監修)、 長尾 高弘 (翻訳)、オライリージャパン)の11章(並行処理とネットワーク)、11.3(復習問題)、11-4を取り組んでみる。

11-4

コード(Emacs)

factory.py

#!/usr/bin/env python3
# -*- coding: utf-8 -*-

import redis
import time
import random

host = 'localhost'
port = 6379

conn = redis.Redis(host=host, port=port)
name = 'chocolates'
conn.delete(name)
chocolates = ['type{0}'.format(i + 1) for i in range(5)]

while True:
    time.sleep(random.random())
    conn.rpush('chocolates', random.choice(chocolates))

lucy.py

#!/usr/bin/env python3
# -*- coding: utf-8 -*-

import redis
import time
import datetime

host = 'localhost'
port = 6379

conn = redis.Redis(host=host, port=port)

name = 'chocolates'
while True:
    t = conn.lpop(name)
    print(datetime.datetime.utcnow())
    print(t.decode('utf-8'))
    l = conn.llen(name)
    time.sleep(0.5)
    print('残り: {0}'.format(l))
    if l == 0:
        print('終了！')
        break

入出力結果(Terminal, IPython)

$ sudo port load redis
$ ./factory.py &
[1] 17569
$ ./lucy.py
2016-09-07 11:25:37.669114
type1
残り: 2
2016-09-07 11:25:38.171688
type2
残り: 2
2016-09-07 11:25:38.678008
type3
残り: 1
2016-09-07 11:25:39.182196
type4
残り: 1
2016-09-07 11:25:39.688896
type2
残り: 3
2016-09-07 11:25:40.195779
type5
残り: 3
2016-09-07 11:25:40.698051
type4
残り: 3
2016-09-07 11:25:41.202121
type1
残り: 2
2016-09-07 11:25:41.703932
type1
残り: 2
2016-09-07 11:25:42.210413
type4
残り: 2
2016-09-07 11:25:42.714215
type1
残り: 3
2016-09-07 11:25:43.216819
type3
残り: 3
2016-09-07 11:25:43.720093
type4
残り: 4
2016-09-07 11:25:44.224166
type2
残り: 4
2016-09-07 11:25:44.726231
type4
残り: 3
2016-09-07 11:25:45.232802
type3
残り: 3
2016-09-07 11:25:45.736205
type4
残り: 2
2016-09-07 11:25:46.238677
type5
残り: 2
2016-09-07 11:25:46.741533
type3
残り: 2
2016-09-07 11:25:47.249328
type4
残り: 2
2016-09-07 11:25:47.751569
type3
残り: 2
2016-09-07 11:25:48.254180
type1
残り: 2
2016-09-07 11:25:48.761652
type1
残り: 3
2016-09-07 11:25:49.265048
type5
残り: 5
2016-09-07 11:25:49.771343
type5
残り: 5
2016-09-07 11:25:50.275476
type4
残り: 5
2016-09-07 11:25:50.778335
type5
残り: 4
2016-09-07 11:25:51.281541
type5
残り: 4
2016-09-07 11:25:51.783742
type2
残り: 4
2016-09-07 11:25:52.289554
type2
残り: 3
2016-09-07 11:25:52.795872
type5
残り: 3
2016-09-07 11:25:53.302913
type5
残り: 3
2016-09-07 11:25:53.809406
type3
残り: 3
2016-09-07 11:25:54.316386
type3
残り: 3
2016-09-07 11:25:54.820813
type3
残り: 2
2016-09-07 11:25:55.327423
type5
残り: 2
2016-09-07 11:25:55.832352
type2
残り: 1
2016-09-07 11:25:56.335538
type5
残り: 2
2016-09-07 11:25:56.839973
type3
残り: 2
2016-09-07 11:25:57.342357
type2
残り: 2
2016-09-07 11:25:57.846712
type3
残り: 1
2016-09-07 11:25:58.353433
type5
残り: 2
2016-09-07 11:25:58.858911
type5
残り: 2
2016-09-07 11:25:59.361614
type2
残り: 1
2016-09-07 11:25:59.866014
type4
残り: 1
2016-09-07 11:26:00.368172
type1
残り: 1
2016-09-07 11:26:00.871562
type5
残り: 0
終了！
$ fg
./factory.py
  C-c C-cTraceback (most recent call last):
  File "./factory.py", line 17, in <module>
    time.sleep(random.random())
KeyboardInterrupt
$ sudo port unload redis
$