NERC / The University of Bristol

Jan 4-6, 2017

9:00 am - 5:00 pm

Instructors: Andrew Walker, Martin Callaghan

Helpers: Alan Baird, Neil Wilkins

General Information

Software Carpentry's mission is to help scientists and engineers get more research done in less time and with less pain by teaching them basic lab skills for scientific computing. This hands-on workshop will cover basic concepts and tools, including program design, version control, data management, and task automation. Participants will be encouraged to help one another and to apply what they have learned to their own research problems.

For more information on what we teach and why, please see our paper "Best Practices for Scientific Computing".

The workshop is funded by NERC as part of the Advanced Training Short Courses programme. Priority will thus be given to NERC-funded PhD students and early career researchers from the environmental sciences who should register below or contact Andrew Walker for further information. Some funding to cover travel and accommodation costs of these participants is available. Any unallocated spaces will be made generally avalable in early June.

Who: The course is aimed at postgraduate students and other scientists who are familiar with basic programming concepts (like loops, conditionals, arrays, and functions) but need help to translate this knowledge into practical tools to help them work more productively. Priority will be given to NERC-funded PhD students and early career researchers from the environmental sciences.

This is the first of two workshops in January aimed at the NERC community and funded by the ATSC scheme. This one is aimed at participants with some knowledge of programming who want to develop knowledge of python, and understanding of good practice in scientific computing or skills using tools such as version control. The workshop held in Bristol two weeks later will be more appropriate for those with less background knowledge. If you are not sure which workshop is best for you please get in touch with us.

Where: School of Earth Sciences, University of Bristol, Wills Memorial Building, Queens Road,Bristol BS8 1RJ. Get directions with OpenStreetMap or Google Maps.

Requirements: Participants must bring a laptop with a Mac, Linux, or Windows operating sytem (not a tablet, Chromebook, etc.) that they have administrative privileges on. They should have a few specific software packages installed (listed below). They are also required to abide by Software Carpentry's Code of Conduct.

Accessibility: We are committed to making this workshop accessible to everybody. The workshop organisers have checked that:

Materials will be provided in advance of the workshop and large-print handouts are available if needed by notifying the organizers in advance. If we can help making learning easier for you (e.g. sign-language interpreters, lactation facilities) please get in touch and we will attempt to provide them.

Contact: Please mail for more information.

We will use this Etherpad for chatting, taking notes, and sharing URLs and bits of code.



Please be sure to complete these surveys before and after the workshop.

Pre-workshop Survey

Post-workshop Survey

Day 1: Wednesday

09:00 Arrival and Welcome
09:30 Using the shell to do more in less time
10:30 Break
10:45 Python and good programming practice (1)
12:30 Lunch (provided)
13:30 Using version control to manage information
15:00 Break
15:15 Python and good programming practice (2)
17:00 Close

Day 2: Thursday

09:00 Recap
09:30 Using version control to share information
10:45 Break
11:00 Testing and Continuous Integration with Python (1)
12:30 Lunch
13:30 Python and the command line
15:00 Break
15:15 Testing and Continuous Integration with Python (2)
16:15 Preperation for day 3
17:00 Close

Day 3: Friday "hack day"

The third day will attendees to begin to work together in small groups to develop useful tools for their own research. We will start with an introduction to the day at 09:00 and have a wrap-up session including time for groups show their progress from about 15:00. We will finish by 17:00 (lunch and breaks will be provided as detailed above).


The Unix Shell

  • Files and directories
  • History and tab completion
  • Pipes and redirection
  • Looping over files
  • Creating and running shell scripts
  • Finding things
  • Reference...

Programming in Python

  • Using libraries
  • Working with arrays
  • Reading and plotting data
  • Creating and using functions
  • Loops and conditionals
  • Defensive programming
  • Using Python from the command line
  • Reference...

Version Control with Git

  • Creating a repository
  • Recording changes to files: add, commit, ...
  • Viewing changes: status, diff, ...
  • Ignoring files
  • Working on the web: clone, pull, push, ...
  • Resolving conflicts
  • Open licenses
  • Where to host work, and why
  • Reference...

Testing and Continuous Integration with Python

  • Basics of testing, assertions and exceptions
  • Unit tests, edge and corner cases, running tests
  • Integration and regression tests
  • Continuous integration
  • Reference...


To participate in a Software Carpentry workshop, you will need access to the software described below. In addition, you will need an up-to-date web browser.

We maintain a list of common issues that occur during installation as a reference for instructors that may be useful on the Configuration Problems and Solutions wiki page.

The Bash Shell

Bash is a commonly-used shell that gives you the power to do simple tasks more quickly.


Video Tutorial
  1. Download the Git for Windows installer.
  2. Run the installer and follow the steps bellow:
    1. Click on "Next".
    2. Click on "Next".
    3. Keep "Use Git from the Windows Command Prompt" selected and click on "Next". If you forgot to do this programs that you need for the workshop will not work properly. If this happens rerun the installer and select the appropriate option.
    4. Click on "Next".
    5. Keep "Checkout Windows-style, commit Unix-style line endings" selected and click on "Next".
    6. Keep "Use Windows' default console window" selected and click on "Next".
    7. Click on "Install".
    8. Click on "Finish".
  3. If your "HOME" environment variable is not set (or you don't know what this is):
    1. Open command prompt (Open Start Menu then type cmd and press [Enter])
    2. Type the following line into the command prompt window exactly as shown:

      setx HOME "%USERPROFILE%"

    3. Press [Enter], you should see SUCCESS: Specified value was saved.
    4. Quit command prompt by typing exit then pressing [Enter]

This will provide you with both Git and Bash in the Git Bash program.

Mac OS X

The default shell in all versions of Mac OS X is Bash, so no need to install anything. You access Bash from the Terminal (found in /Applications/Utilities). See the Git installation video tutorial for an example on how to open the Terminal. You may want to keep Terminal in your dock for this workshop.


The default shell is usually Bash, but if your machine is set up differently you can run it by opening a terminal and typing bash. There is no need to install anything.


Git is a version control system that lets you track who made changes to what when and has options for easily updating a shared or public version of your code on You will need a supported web browser (current versions of Chrome, Firefox or Safari, or Internet Explorer version 9 or above).

You will need an account at for parts of the Git lesson. Basic GitHub accounts are free. We encourage you to create a GitHub account if you don't have one already. Please consider what personal information you'd like to reveal. For example, you may want to review these instructions for keeping your email address private provided at GitHub.


Git should be installed on your computer as part of your Bash install (described above).

Mac OS X

Video Tutorial

For OS X 10.9 and higher, install Git for Mac by downloading and running the most recent "mavericks" installer from this list. After installing Git, there will not be anything in your /Applications folder, as Git is a command line program. For older versions of OS X (10.5-10.8) use the most recent available installer labelled "snow-leopard" available here.


If Git is not already available on your machine you can try to install it via your distro's package manager. For Debian/Ubuntu run sudo apt-get install git and for Fedora run sudo yum install git.

Text Editor

When you're writing code, it's nice to have a text editor that is optimized for writing code, with features like automatic color-coding of key words. The default text editor on Mac OS X and Linux is usually set to Vim, which is not famous for being intuitive. if you accidentally find yourself stuck in it, try typing the escape key, followed by :q! (colon, lower-case 'q', exclamation mark), then hitting Return to return to the shell.


Video Tutorial

nano is a basic editor and the default that instructors use in the workshop. To install it, download the Software Carpentry Windows installer and double click on the file to run it. This installer requires an active internet connection.

Others editors that you can use are Notepad++ or Sublime Text. Be aware that you must add its installation directory to your system path. Please ask your instructor to help you do this.

Mac OS X

nano is a basic editor and the default that instructors use in the workshop. See the Git installation video tutorial for an example on how to open nano. It should be pre-installed.

Others editors that you can use are Text Wrangler or Sublime Text.


nano is a basic editor and the default that instructors use in the workshop. It should be pre-installed.

Others editors that you can use are Gedit, Kate or Sublime Text.


Python is a popular language for scientific computing, and great for general-purpose programming as well. Installing all of its scientific packages individually can be a bit difficult, so we recommend Anaconda, an all-in-one installer.

Regardless of how you choose to install it, please make sure you install Python version 3.x (e.g., 3.4 is fine).

We will teach Python using the IPython notebook, a programming environment that runs in a web browser. For this to work you will need a reasonably up-to-date browser. The current versions of the Chrome, Safari and Firefox browsers are all supported (some older browsers, including Internet Explorer version 9 and below, are not).


Video Tutorial
  1. Open with your web browser.
  2. Download the Python 3 installer for Windows.
  3. Install Python 3 using all of the defaults for installation except make sure to check Make Anaconda the default Python.

Mac OS X

Video Tutorial
  1. Open with your web browser.
  2. Download the Python 3 installer for OS X.
  3. Install Python 3 using all of the defaults for installation.


  1. Open with your web browser.
  2. Download the Python 3 installer for Linux.
  3. Install Python 3 using all of the defaults for installation. (Installation requires using the shell. If you aren't comfortable doing the installation yourself stop here and request help at the workshop.)
  4. Open a terminal window.
  5. Type
    bash Anaconda3-
    and then press tab. The name of the file you just downloaded should appear.
  6. Press enter. You will follow the text-only prompts. When there is a colon at the bottom of the screen press the down arrow to move down through the text. Type yes and press enter to approve the license. Press enter to approve the default location for the files. Type yes and press enter to prepend Anaconda to your PATH (this makes the Anaconda distribution the default Python).

Once you are done installing the software listed above, please go to this page, which has instructions on how to test that everything was installed correctly.

Before the workshop

There are a three extra tasks to undertake before the workshop in order to help make sure things run smoothly. Please try to do the following.

1. Grab free accounts

If you haven't already, please register for free accounts to

  • Make use of Github. Register here and don't forget your password. We will use this service as part of the lesson on version control.
  • Use the Met Office datapoint API. Register for an account here. We may use this as a data source for some of the exercises.

2. Take a look at Bash, and maybe look at Python

We would like to get started with bash quickly at the start of the workshop. It would be useful if everybody could take a look at the first three shell lessons, found here, here, and here, to either remind yourself of how a shell works, or to have a first look if this is new to you.

If you are new to Python, or you fear that your Python is rusty, you wil need to take a look at an online introduction. Christopher Woods has a nice short introduction here. If you can follow this as far as "conditions", you are good to go. We will be reviewing this material anyway, so don't worry if you get stuck.

3. Tell us about yourself

Finally, please compleate the pre-workshop survay here

During and after the workshop

We have gathered together the various links you will need and useful information below. These will remain accessable after the workshop and we will add to this list as the workshop progresses. Please read and abide by the code of conduct.

We will make use of this etherpad during the workshop. Please use this to keep collaborative notes and ask (and answer) each others questions. Feel free to tweet from the workshop using #SWCLeeds.

Workshop material

Much of the material we will be using during the workshop can be found online and you will need copies of this on your laptop. In order to download the material for the first session on bash (and to check you have a working system with internet access) please start a new shell and type the following commands:

cd Desktop
git clone
cd shell-training
(typing return after each line). You should see something like "repository successfully cloned". Let us know if this does not work for you.

The python material is is avalable in the same way. To get hold of the data (and the files we created during the workshop) type:

cd Desktop
git clone
cd 2017-01-04-python1

The testing material is is avalable in the same way:

cd Desktop
git clone
cd 2017-01-04-python1

Stuck somewhere new?

If you find yourself in a shell that you don't recognise, or in an editor that you can't get out of then see recognising prompts and how to exit.

Useful links

Software Carpentry online lessions:




Papers and books

Wilson G, Aruliah DA, Brown CT, Chue Hong NP, Davis M, et al. (2014) Best Practices for Scientific Computing. PLoS Biol 12(1): e1001745. doi:10.1371/journal.pbio.1001745.

Sandve GK, Nekrutenko A, Taylor J, Hovig E (2013) Ten Simple Rules for Reproducible Computational Research. PLoS Comput Biol 9(10): e1003285. doi:10.1371/journal.pcbi.1003285.

Noble WS (2009) A Quick Guide to Organizing Computational Biology Projects. PLoS Comput Biol 5(7): e1000424. doi:10.1371/journal.pcbi.1000424.

Ram K (2013) "git can facilitate greater reproducibility and increased transparency in science", Source Code for Biology and Medicine 2013, 8:7 doi:10.1186/1751-0473-8-7.

Glass, R. (2002) Facts and Fallacies of Software Engineering, Addison-Wesley, 2002. (PDF).

Scopatz, A. and Huff, K. D. (2015) Effective computation in physics, O'Reilly.