hrldcpr

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!

jacobsandlund

#!/bin/sh

# This shows how to handle combined short options along with 
# other long and short options. It does so by splitting them 
# apart (e.g. 'tar -xvzf ...' -> 'tar -x -v -z -f ...')

while test $# -gt 0
do
  case $1 in

jboner

Latency Comparison Numbers (~2012)
----------------------------------
L1 cache reference                           0.5 ns
Branch mispredict                            5   ns
L2 cache reference                           7   ns                      14x L1 cache
Mutex lock/unlock                           25   ns
Main memory reference                      100   ns                      20x L2 cache, 200x L1 cache
Compress 1K bytes with Zippy             3,000   ns        3 us
Send 1K bytes over 1 Gbps network       10,000   ns       10 us
Read 4K randomly from SSD*             150,000   ns      150 us          ~1GB/sec SSD

dougvk

import re
from cPickle import dump
from requests import get

DEFAULT_TICKERS = ['goog', 'aapl']
URL = 'http://www.sec.gov/cgi-bin/browse-edgar?CIK={}&Find=Search&owner=exclude&action=getcompany'
CIK_RE = re.compile(r'.*CIK=(\d{10}).*')

cik_dict = {}
for ticker in DEFAULT_TICKERS:

jiffyclub

function condalist -d 'List conda environments.'
  for dir in (ls $HOME/miniconda3/envs)
    echo $dir
  end
end

function condactivate -d 'Activate a conda environment' -a cenv
  if test -z $cenv
    echo 'Usage: condactivate <env name>'
    return 1

staltz

The introduction to Reactive Programming you've been missing

(by @andrestaltz)

---

This tutorial as a series of videos

If you prefer to watch video tutorials with live-coding, then check out this series I recorded with the same contents as in this article: Egghead.io - Introduction to Reactive Programming.

---

TheSeamau5

#Exploring Entity Component Systems in Elm

Entity-Component-System (or ECS) is a pattern for designing programs that is prevalent in the games industry. This pattern consists of three simple parts:

• Entity : A uniquely identifiable object that may contain any number of components
• Component : A property usually representing the raw data of one aspect of the object. (Position is a component, Velocity is a component, Strength is a component, etc...)
• System : A continuous process performing actions on every entity that possesses a component of the same aspect as that system

To understand this, let us try to make a simple example: Boxes that move in space:

allj

import os
import opengl
import glfw/wrapper as glfw


template `&`[T](v: var T): ptr[T] = addr(v)
template `*`[T](v: ptr[T]): T = v[]
template `*`[T](v: ref[T]): T = v[]

karpathy

"""
Minimal character-level Vanilla RNN model. Written by Andrej Karpathy (@karpathy)
BSD License
"""
import numpy as np

# data I/O
data = open('input.txt', 'r').read() # should be simple plain text file
chars = list(set(data))
data_size, vocab_size = len(data), len(chars)

hnykda

import pandas as pd  
from random import random

flow = (list(range(1,10,1)) + list(range(10,1,-1)))*100
pdata = pd.DataFrame({"a":flow, "b":flow})  
pdata.b = pdata.b.shift(9)  
data = pdata.iloc[10:] * random()  # some noise  

import numpy as np