Ricardo Napoli rnapoli

Latency Comparison Numbers

Note: "Forked" from Latency Numbers Every Programmer Should Know

Event	Nanoseconds	Microseconds	Milliseconds	Comparison
L1 cache reference	0.5	-	-	-
Branch mispredict	5.0	-	-	-
L2 cache reference	7.0	-	-	14x L1 cache
Mutex lock/unlock	25.0	-	-	-

How to update a GitHub forked repository?

So you hit "Fork" and now you have this repo copy on your Github account. Here is what to do to keep it up-to-date with the original repo.

1. Add the original repo as remote, here called upstream:

git remote add upstream https://github.com/author/repo.git

2. Fetch all the branches of that upstream remote:

Raspberry Pi Zero OTG Mode

Simple guide for setting up OTG modes on the Raspberry Pi Zero - By Andrew Mulholland (gbaman).

The Raspberry Pi Zero (and model A and A+) support USB On The Go, given the processor is connected directly to the USB port, unlike on the B, B+ or Pi 2 B, which goes via a USB hub.
Because of this, if setup to, the Pi can act as a USB slave instead, providing virtual serial (a terminal), virtual ethernet, virtual mass storage device (pendrive) or even other virtual devices like HID, MIDI, or act as a virtual webcam!
It is important to note that, although the model A and A+ can support being a USB slave, they are missing the ID pin (is tied to ground internally) so are unable to dynamically switch between USB master/slave mode. As such, they default to USB master mode. There is no easy way to change this right now.
It is also important to note, that a USB to UART serial adapter is not needed for any of these guides, as may be documented elsewhere across the int

This gist contains lists of modules available in

Python 3.10
Python 3.9
Python 3.8
Python 3.7
Python 3.6
Python 2.7

in AWS Lambda.

MySQL Dump

This shade of green happens to correspond to mostly-ASCII characters.

GPG Encryption

Symmetric (gpg -c) encryption of the above MySQL dump.

	#!/usr/bin/env python3

	import os
	import sys
	import click
	import subprocess
	import tempfile
	import itertools as IT
	import select
	from time import sleep

	def remove_empty_elements(d):
	"""recursively remove empty lists, empty dicts, or None elements from a dictionary"""

	def empty(x):
	return x is None or x == {} or x == []

	if not isinstance(d, (dict, list)):
	return d
	elif isinstance(d, list):
	return [v for v in (remove_empty_elements(v) for v in d) if not empty(v)]