wmjie wmjie

Easy parallel python with concurrent.futures

As of version 3.3, python includes the very promising concurrent.futures module, with elegant context managers for running tasks concurrently. Thanks to the simple and consistent interface you can use both threads and processes with minimal effort.

For most CPU bound tasks - anything that is heavy number crunching - you want your program to use all the CPUs in your PC. The simplest way to get a CPU bound task to run in parallel is to use the ProcessPoolExecutor, which will create enough sub-processes to keep all your CPUs busy.

We use the context manager thusly:

with concurrent.futures.ProcessPoolExecutor() as executor:

##ss-redir 的 iptables 配置(透明代理)

透明代理指对客户端透明，客户端不需要进行任何设置就使用了网管设置的代理规则

创建 /etc/ss-redir.json 本地监听 7777 运行ss-redir -v -c /etc/ss-redir.json

iptables -t nat -N SHADOWSOCKS
# 在 nat 表中创建新链
iptables -t nat -A SHADOWSOCKS -p tcp --dport 23596 -j RETURN
# 23596 是 ss 代理服务器的端口，即远程 shadowsocks 服务器提供服务的端口，如果你有多个 ip 可用,但端口一致，就设置这个

The Best of the Best Practices (BOBP) Guide for Python

A "Best of the Best Practices" (BOBP) guide to developing in Python.

In General

Values

"Build tools for others that you want to be built for you." - Kenneth Reitz
"Simplicity is alway better than functionality." - Pieter Hintjens

One-line Tree in Python

Using Python's built-in defaultdict we can easily define a tree data structure:

def tree(): return defaultdict(tree)

That's it!

	import _winreg as reg
	import win32file


	adapter_key = r'SYSTEM\CurrentControlSet\Control\Class\{4D36E972-E325-11CE-BFC1-08002BE10318}'


	def get_device_guid():
	with reg.OpenKey(reg.HKEY_LOCAL_MACHINE, adapter_key) as adapters:
	try:

	import asyncio

	@asyncio.coroutine
	def waiting(r):
	print("hello from waiting -", r)
	yield from asyncio.sleep(2)
	print("bye from waiting -", r)
	return r

	import _winreg as reg
	import win32file


	adapter_key = r'SYSTEM\CurrentControlSet\Control\Class\{4D36E972-E325-11CE-BFC1-08002BE10318}'


	def get_device_guid():
	with reg.OpenKey(reg.HKEY_LOCAL_MACHINE, adapter_key) as adapters:
	try:

	import fcntl
	import os
	import struct
	import subprocess


	# Some constants used to ioctl the device file. I got them by a simple C
	# program.
	TUNSETIFF = 0x400454ca
	TUNSETOWNER = TUNSETIFF + 2