Andrew sheerluck

Dplyr (R), Pandas (Python) & Nim data frame comparison

This comparison is inspired by the comparison here: https://gist.github.com/conormm/fd8b1980c28dd21cfaf6975c86c74d07

The Nim data frame implementation we use here is the Datamancer data frame.

Note that due to UFCS in Nim we can write the commands we present either similar to the Python notation as if the function were a method of the

FFMPEG to DVD

This is the default for most movies.

Scope Movies

ffmpeg -y -i {Input} -vf scale=720:352,pad=720:480:0:64 \
-target film-dvd -vb 4M -aspect 1.7777 -ac 2 -ab 192k {Output}

Latency numbers every programmer should know

L1 cache reference ......................... 0.5 ns
Branch mispredict ............................ 5 ns
L2 cache reference ........................... 7 ns
Mutex lock/unlock ........................... 25 ns
Main memory reference ...................... 100 ns             
Compress 1K bytes with Zippy ............. 3,000 ns  =   3 µs
Send 2K bytes over 1 Gbps network ....... 20,000 ns  =  20 µs
SSD random read ........................ 150,000 ns  = 150 µs

Read 1 MB sequentially from memory ..... 250,000 ns = 250 µs

$ curl -s -H "X-Something: yeah" localhost:8000 > /dev/null

$ python serv.py
ERROR:root:User-Agent: curl/7.37.1
Host: localhost:8000
Accept: */*
X-Something: yeah

	#!/usr/bin/env python
	# -- coding: UTF-8 --

	# Convert ShiftJIS to UTF-8
	# Usage: cat ShiftJIS.txt \| ./convert.py > UTF8.txt
	# Alternative method: cat ShiftJIS.txt \| iconv -f shift_jis -t utf8 > UTF8.txt

	import sys
	import codecs

	#!/usr/bin/python3
	#
	# usage: python3 docker_descendants.py <image_id> ...

	import sys
	from subprocess import check_output


	def main(images):
	image_ids = set(images)

	class Maybe[A : Equatable[A] val] is Equatable[Maybe[A]]
	let v : (A val \| None)

	new val create(thing: A) => v = thing
	new val empty() => v = None

	fun eq(that: box->Maybe[A]): Bool =>
	match (this.v, that.v)
	\| (let v' : A, let v'' : A) => v' == v''
	\| (let n' : None, let n'' : None) => true

	# #!/bin/bash

	GITBOOK_REP=$1
	SUMMARY_FILE="SUMMARY.md"
	echo $OUTPUT_FILE

	if [ -d "$GITBOOK_REP" ]; then

	echo "Entering directory '$GITBOOK_REP'..."
	cd $GITBOOK_REP

-from pyrabbit.api import Client
-username = 'guest'
-password = 'guest'
-cl = Client('localhost:15672', username, password)
-queues = [q['name'] for q in cl.get_queues()]
-for q in queues:
-  #if q.startswith('Dispatch.259'):
-    print ('deleting...' + q)
-    cl.delete_queue('/', q)