Saswata Dutta saswata-dutta

This gist contains lists of modules available in

Python 2.7
Python 3.6
Python 3.7

in AWS Lambda.

It also contains the code to run in Lambda to generate these lists. In addition there is a less_versbose module in the code that you can call to get a list of the top level modules installed and the version of those modules (if they contain a version

Working Effectively with Legacy Code

Notes by Jeremy W. Sherman, October 2013, based on:

Feathers, Michael. Working Effectively with Legacy Code. Sixth printing, July 2007.

Foreword:

Software systems degrade into a mess.
Requirements ALWAYS change.
Your goal as a software developer: Create designs that tolerate change.

Internet Scale Services Checklist

A checklist for designing and developing internet scale services, inspired by James Hamilton's 2007 paper "On Desgining and Deploying Internet-Scale Services."

http://mvdirona.com/jrh/talksandpapers/jamesrh_lisa.pdf

Basic tenets

Does the design expect failures to happen regularly and handle them gracefully?
Have we kept things as simple as possible?

Advanced Distributed System Design Course - Udi Dahan

Notes by Craig Phillips

Fallacies of Distributed Computing

There are 11 fallacies of Distributed Computing:
1. The network is reliable
2. Latency isn’t a problem
3. Bandwidth isn’t a problem
4. The network is secure

The topology won’t change

Pipenv Cheat Sheet

Install pipenv

pip3 install pipenv

Activate

pipenv shell

How to get a stack trace for each thread in a running Python script

Sometimes a Python script will simply hang forever with no indication of what is going wrong. Perhaps it's polling a service that will never return a value that allows the program to move forward.

Here's a way to see where the program is currently stuck, using pyrasite a tool for injecting code into running Python processes.

Install gdb and pyrasite

Install gdb.

	#!/usr/bin/env python2.7

	import time

	_URL = 'http://localhost/tmp/derp.html'
	_NUMBER = 1000


	def test_urllib2():
	import urllib2

	public final class ResultFuture implements Future<Result> {
	private final CountDownLatch latch = new CountDownLatch(1);
	private Result value;

	@Override
	public boolean cancel(boolean mayInterruptIfRunning) {
	return false;
	}

	@Override

	// A simple thread-safe queue implementation based on std::list<>::splice
	// after a tip in a talk by Sean Parent of Adobe.
	//
	// Uses standard library threading and synchronization primitives together
	// with a std::list<> container for implementing a thread-safe queue. The
	// only special thing is that the queue uses std::list<>::splice in the
	// locked region to minimize locked time.
	//
	// Also implements a maximal size and can thus be used as a buffer between
	// the elements in a pipeline with limited buffer bloat.

	# Credit for this: Nicholas Swift
	# as found at https://medium.com/@nicholas.w.swift/easy-a-star-pathfinding-7e6689c7f7b2
	from warnings import warn
	import heapq

	class Node:
	"""
	A node class for A* Pathfinding
	"""