Hugo Hromic hhromic

Cheat Sheet for Python Time Data

Note: These snippets are tested with Python 3, which has better datetime object support than Python 2.

Textual Time to `datetime` Object

from datetime import datetime

# example Twitter "created_at" field time format

Publishing to PyPi

Update code
Update version number in setup.py or setup.cfg
Commit all changes: git commit -a
Tag the current state with version number: git tag X.Y.Z
Push changes to remote: git push --tags
Build source distribution: python setup.py sdist bdist_wheel
Release to PyPi: twine upload dist/*
Update GitHub release with notes and other stuff

Slimming Down Raspbian Stretch Lite

Notes for slimming down a fresh installation of Raspbian Stretch Lite. This guide does not strip Raspbian of basic functionality such as Bluetooth and mDNS.

Instructions

Install a fresh Raspbian Stretch Lite image into the SD card ([source][1]).

$ unzip -p 2018-04-18-raspbian-stretch-lite.zip | dd bs=4M of=/dev/sdX conv=fsync

Repositories Cloning

BRANCH=master  # or 'rocko'
xargs -n 1 git clone -b $BRANCH <<'__EOF__'
git://git.yoctoproject.org/poky
git://git.openembedded.org/meta-openembedded
git://github.com/agherzan/meta-raspberrypi
git://github.com/webplatformforembedded/meta-wpe
__EOF__

Useful LaTeX Snippets

About Lenghts

From https://tex.stackexchange.com/a/16956:

\textwidth is generally the global width of the text area, while \columnwidth is the width of a column of text (it will be different from \textwidth when typesetting in two or more columns). However, inside a minipage, \textwidth will be set to the given argument along with \hsize, \columnwidth, and \linewidth (they will revert to the previous values at the end of the minipage because it forms a group). Note that \parbox doesn't reset \textwidth; the size is available as \linewidth.

The parameter \linewidth contains the line length inside a list (or derived) environment and it may change in a nested list (while \hsize, \textwidth and \columnwidth don't change). >

Working with Disk Images in Linux

Ref: https://www.linuxquestions.org/questions/linux-general-1/how-to-mount-img-file-882386/#post4365399

To list the partitions of a disk image:

$ fdisk -l mydisk.img
Disk mydisk.img: 15 GiB, 16088301568 bytes, 31422464 sectors
Units: sectors of 1 * 512 = 512 bytes

Sector size (logical/physical): 512 bytes / 512 bytes

	# Please make this file available to others
	# by sending it to <[email protected]>
	#
	# this config file was automatically generated
	# using lirc-0.9.0(default) on Sun Feb 21 02:54:40 2016
	#
	# contributed by http://github.com/hhromic
	#
	# brand: Dell
	# model no. of remote control: Dell Travel Remote NU-851

	import sys
	import multiprocessing
	import tqdm
	import snap

	# the graph needs to be global so workers can access it after forking
	GRAPH = None

	# task: compute eccentricy of a node
	def compute_ecc(node_id):

	import msgpack

	def _encode_ext_type(obj):
	if isinstance(obj, set): # encode 'set' with typecode 10
	return msgpack.ExtType(10, packb(tuple(obj)))
	raise TypeError("unknown extended type for %r" % type(obj))

	def _decode_ext_type(typecode, data):
	if typecode == 10: # decode a 'set' type
	return set(unpackb(data))

	#!/usr/bin/env bash
	# Show the current capacity of all managed batteries
	# script by github.com/hhromic

	POWER_SUPPLY_DIR=/sys/class/power_supply
	mapfile -t CAPACITIES < <(compgen -G "$POWER_SUPPLY_DIR"/'*'/capacity)

	for capacity in "${CAPACITIES[@]}"; do
	battery="${capacity%/*}"
	battery="${battery##*/}"