Nick Sweeting pirate

How to recover lost Python source code if it's still resident in-memory

I screwed up using git ("git checkout --" on the wrong file) and managed to delete the code I had just written... but it was still running in a process in a docker container. Here's how I got it back, using https://pypi.python.org/pypi/pyrasite/ and https://pypi.python.org/pypi/uncompyle6

Attach a shell to the docker container

Install GDB (needed by pyrasite)

apt-get update && apt-get install gdb

Exporting your 2FA tokens from Authy to transfer them into another 2FA application

IMPORTANT - Update regarding deprecation of Authy desktop apps

Past August 2024, Authy stopped supported the desktop version of their apps:
See Authy is shutting down its desktop app | The 2FA app Authy will only be available on Android and iOS starting in August for details.

And indeed, after a while, Authy changed something in their backend which now prevents the old desktop app from logging in. If you are already logged in, then you are in luck, and you can follow the instructions below to export your tokens.

If you are not logged in anymore, but can find a backup of the necessary files, then restore those files, and re-install Authy 2.2.3 following the instructions below, and it should work as expected.

Python’s lru_cache is sensitive to order of keyword arguments

In case you were wondering, Python’s built-in LRU cache function decorator doesn’t cache function calls with the same keyword arguments written in a different order. That is, if you cache a function and then call it twice, with the same keyword arguments but written in a different order, on the second call you won’t get the cached result and the function will be re-run.

proof/example

Let’s construct an example. We’re interested in keyword arguments, so we’ll make our function only take keyword arguments (1). We want some side-effect to tell us whether it was a cache hit or miss, so we’ll print each keyword when we iterate over it (2). We want to cache a result, so we’ll return the sum of the values of the keyword arguments (3). Finally, we apply the lru_cache decorator to the function with a maxsize=None to let the cache grow unbounded. Putting all that together, we get:

	function getUrlParams(search) {
	const hashes = search.slice(search.indexOf('?') + 1).split('&')
	const params = {}
	hashes.map(hash => {
	const [key, val] = hash.split('=')
	params[key] = decodeURIComponent(val)
	})
	return params
	}

	# -- coding: utf-8 --
	from __future__ import unicode_literals
	import uuid

	from django.db import migrations, models


	def fill_mymodel_uuid(apps, schema_editor):
	db_alias = schema_editor.connection.alias
	MyModel = apps.get_model('myapp', 'MyModel')

	#!/bin/bash

	# Before running this script:
	# Find AC_CHECK_FILES([/proc/self/stat]) in configure.ac and comment it out
	# cd into the fish source directory

	FLAGS="-stdlib=libc++ -isysroot /Applications/Xcode.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS.sdk -target armv7-apple-darwin16 -miphoneos-version-min=8.0.0"
	PREFIX=$(pwd)"/deb"

	# Build fish

	'''
	Run the following commands (bc. gists don't allow directories)

	pip install flask django dj-database-url psycopg2

	mkdir -p app/migrations
	touch app/__init__.py app/migrations/__init__.py
	mv models.py app/
	python manage.py makemigrations
	python manage.py migrate

	#!/usr/bin/python3
	#
	# Simple Bloom filter implementation in Python 3
	# Copyright 2017 Hector Martin "marcan" <[email protected]>
	# Licensed under the terms of the MIT license
	#
	# Written to be used with the Have I been pwned? password list:
	# https://haveibeenpwned.com/passwords
	#
	# Download the pre-computed filter here (968MB, k=11, false positive p=0.0005):

	# Description: Boxstarter Script
	# Author: Jess Frazelle <[email protected]>
	# Last Updated: 2017-09-11
	#
	# Install boxstarter:
	# . { iwr -useb http://boxstarter.org/bootstrapper.ps1 } \| iex; get-boxstarter -Force
	#
	# You might need to set: Set-ExecutionPolicy RemoteSigned
	#
	# Run this boxstarter by calling the following from an elevated command-prompt:

	import sys

	def j(lineno):
	frame = sys._getframe().f_back
	called_from = frame

	def hook(frame, event, arg):
	if event == 'line' and frame == called_from:
	try:
	frame.f_lineno = lineno