garybernhardt

This document has moved!

It's now here, in The Programmer's Compendium. The content is the same as before, but being part of the compendium means that it's actively maintained.

stevecaldwell77

CloudFormation snippet to create a VPC to be used for lambda functions. Qualities of the VPC:

• 4 subnets: 2 public, 2 private (lambda functions should be attached to the private ones).
• 2 Elastic IPs that can be used to identify traffic coming from lambda functions (e.g. for firewall holes).
• Security group that can be used for lambda functions.

Notes:

• uses regions us-east-1a, us-east-1b
• uses ip block of 10.15.0.0/16 for VPC

reggi

How to setup AWS lambda function to talk to the internet and VPC

I'm going to walk you through the steps for setting up a AWS Lambda to talk to the internet and a VPC. Let's dive in.

So it might be really unintuitive at first but lambda functions have three states.

1. No VPC, where it can talk openly to the web, but can't talk to any of your AWS services.
2. VPC, the default setting where the lambda function can talk to your AWS services but can't talk to the web.
3. VPC with NAT, The best of both worlds, AWS services and web.

karpathy

""" Trains an agent with (stochastic) Policy Gradients on Pong. Uses OpenAI Gym. """
import numpy as np
import cPickle as pickle
import gym

# hyperparameters
H = 200 # number of hidden layer neurons
batch_size = 10 # every how many episodes to do a param update?
learning_rate = 1e-4
gamma = 0.99 # discount factor for reward

vasanthk

System Design Cheatsheet

Picking the right architecture = Picking the right battles + Managing trade-offs

Basic Steps

1. Clarify and agree on the scope of the system

• User cases (description of sequences of events that, taken together, lead to a system doing something useful)
  • Who is going to use it?
  • How are they going to use it?

CMCDragonkai

HTTP Streaming (or Chunked vs Store & Forward)

The standard way of understanding the HTTP protocol is via the request reply pattern. Each HTTP transaction consists of a finitely bounded HTTP request and a finitely bounded HTTP response.

However it's also possible for both parts of an HTTP 1.1 transaction to stream their possibly infinitely bounded data. The advantages is that the sender can send data that is beyond the sender's memory limit, and the receiver can act on

Miserlou

[
    {
        "city": "New York", 
        "growth_from_2000_to_2013": "4.8%", 
        "latitude": 40.7127837, 
        "longitude": -74.0059413, 
        "population": "8405837", 
        "rank": "1", 
        "state": "New York"
    }, 

derhuerst

Installing zsh – the easy way

The Z shell (zsh) is a Unix shell [...]. Zsh can be thought of as an extended Bourne shell with a large number of improvements, including some features of bash, ksh, and tcsh.

– Z shell – Wikipedia

Read more about ZSH at An Introduction to the Z Shell.

Choose one of the following options.

lukehoban

// ES6 w/ Promises
// Note: From a React starter template - see https://t.co/wkStq8y3I5
function fetchData(routes, params) {
  let data = {};

  return Promise.all(routes
    .filter(route => route.handler.fetchData)
    .map(route => {
      return route.handler.fetchData(params).then(resp => {
        data[route.name] = resp;

hectorperez

copy/delete word under cursor in Vim
yw / byw

Assuming that the cursor is at the first character of the word simply do this in command mode:
     yw
y is for yank and w is for word.

Other ways of doing the same thing which are not as efficient:
     vey
the v starts visual select mode. e tells vim to move to end of word. y yanks or copies the word. to delete replace y with x.