ljaniec ljaniec

Falsehoods programmers believe about time

This is a compiled list of falsehoods programmers tend to believe about working with time.

Don't re-invent a date time library yourself. If you think you understand everything about time, you're probably doing it wrong.

Falsehoods

There are always 24 hours in a day.
February is always 28 days long.
Any 24-hour period will always begin and end in the same day (or week, or month).

To remove a submodule you need to:

Delete the relevant section from the .gitmodules file.
Stage the .gitmodules changes git add .gitmodules
Delete the relevant section from .git/config.
Run git rm --cached path_to_submodule (no trailing slash).
Run rm -rf .git/modules/path_to_submodule (no trailing slash).
Commit git commit -m "Removed submodule "
Delete the now untracked submodule files rm -rf path_to_submodule

Git Submodules - Basic Explanation

Why submodules?

In Git you can add a submodule to a repository. This is basically a sub-repository embedded in your main repository. This can be very useful. A couple of usecases of submodules:

Separate big codebases into multiple repositories.

	# https://ros.org/reps/rep-2001.html#simulation
	FROM osrf/ros:humble-simulation

	# https://answers.ros.org/question/411908/running-humble-on-turtlebot3/

	# Install colcon_cd
	RUN apt update
	RUN apt install -y python3-colcon-common-extensions

	# Set up colcon_cd for future bash sessions

	#!/usr/bin/env python3
	#
	# model-training.py
	# Use HyperOpt and Gazebo to train parameters of your robot. Perfoms a number
	# of episodic simulations and optimizing the inputs to a xacro-enabled urdf file.
	#
	# Copyright 2020 FlyingEinstein.com
	# Author: Colin F. MacKenzie
	#
	# Features:

	#!/usr/bin/env python

	from __future__ import print_function

	import rospy
	from concurrent.futures import ThreadPoolExecutor

	class AsyncServiceProxy(object):
	"""Asynchronous ROS service proxy

	FROM ros:indigo-ros-base
	# install ros tutorials packages
	RUN apt-get update && apt-get install -y \
	ros-indigo-ros-tutorials \
	ros-indigo-common-tutorials \
	&& rm -rf /var/lib/apt/lists/