This page will walk you through what you need to do if you want to be able to contribute code or documentation to the PUDL project.
These instructions assume that you are working on a Unix-like operating system (MacOS
or Linux) and are already familiar with
git, GitHub, and the Unix shell.
While it should be possible to set up the development environment on Windows, we haven’t done it. In the future we may create a Docker image that provides the development environment. E.g. for use with VS Code’s Containers extension.
If you’re new to
git and GitHub , you’ll want to
We use the
mamba package manager to specify and update our development
environment, preferentially installing packages from the community maintained
conda-forge distribution channel. We recommend
using mambaforge rather than
miniconda or the large pre-defined
collection of scientific packages bundled together in the Anaconda Python distribution
because it’s faster.
After installing your package manager, make sure it’s configured to use strict channel priority with the following commands:
$ mamba update mamba $ conda config --set channel_priority strict
Fork and Clone the PUDL Repository#
Unless you’re part of the Catalyst Cooperative organization already, you’ll need to fork the PUDL repository This makes a copy of it in your personal (or organizational) account on GitHub that is independent of, but linked to, the original “upstream” project.
Then, clone the repository from your fork to your local computer where you’ll be editing the code or docs. This will download the whole history of the project, including the most recent version, and put it in a local directory where you can make changes.
Create the PUDL Dev Environment#
devtools directory of your newly cloned repository, you’ll see
environment.yml file that specifies the
environment. You can create and activate that environment from within the
main repository directory by running:
$ mamba update mamba $ mamba env create --name pudl-dev --file devtools/environment.yml $ mamba activate pudl-dev
This environment installs the
catalystcoop.pudl package directly using the code in
your cloned repository so that it can be edited during development. It also installs all
of the software PUDL depends on, some packages for testing and quality control, packages
for working with interactive Jupyter Notebooks, and a few Python packages that have
binary dependencies which can be easier to satisfy through
Updating the PUDL Dev Environment#
You will need to periodically update your development (
environment to get you newer versions of existing dependencies and
incorporate any changes to the environment specification that have been
made by other contributors. The most reliable way to do this is to remove the
existing environment and recreate it.
Different development branches within the repository may specify their own
slightly different versions of the
pudl-dev conda environment. As a
result, you may need to update your environment when switching from one
branch to another.
If you want to work with the most recent version of the code on a branch
new-feature, then from within the top directory of the PUDL
repository you would do:
$ git checkout new-feature $ git pull $ mamba deactivate $ mamba update mamba $ mamba env remove --name pudl-dev $ mamba env create --name pudl-dev --file devtools/environment.yml $ mamba activate pudl-dev
If you are working with locally processed data and there have been changes to the expectations about that data in the PUDL software, you may also need to regenerate your PUDL SQLite database or other outputs. See Running the ETL Pipeline for more details.
Set Up Code Linting#
We use several automated tools to apply uniform coding style and formatting
across the project codebase. This is known as
code linting, and it reduces
merge conflicts, makes the code easier to read, and helps catch some types of
bugs before they are committed. These tools are part of the
environment and their configuration files are checked into the GitHub
repository. If you’ve cloned the pudl repo and are working inside the pudl conda
environment, they should be installed and ready to go.
Git Pre-commit Hooks#
Git hooks let you automatically run scripts at various points as you manage your source code. “Pre-commit” hook scripts are run when you try to make a new commit. These scripts can review your code and identify bugs, formatting errors, bad coding habits, and other issues before the code gets checked in. This gives you the opportunity to fix those issues before publishing them.
To make sure they are run before you commit any code, you need to enable the pre-commit hooks scripts with this command:
$ pre-commit install
The scripts that run are configured in the
The pre-commit project: A framework for managing and maintaining multi-language pre-commit hooks.
Real Python Code Quality Tools and Best Practices gives a good overview of available linters and static code analysis tools.
Code and Docs Linters#
Flake8 is a popular Python
linting framework, with a
large selection of plugins. We use it to check the formatting and syntax of
the code and docstrings embedded within the PUDL packages.
Doc8 is a lot like flake8, but for Python
documentation written in the reStructuredText format and built by
Sphinx. This is the de-facto
standard for Python documentation. The
doc8 tool checks for syntax errors
and other formatting issues in the documentation source files under the
We are using the the black code formatter
and style. It’s automatically applied by oure pre-commit hooks, and can probably be
integrated directly into your code editor. Similarly isort automatically groups and orders Python
import statements in each module to minimize diffs and merge conflicts. Note that both
flake8 need to be set up to work well with
black – but those
configurations are stored in the PUDL repository, so you should be able to point your
editor at those configuration files (
pyproject.toml) to get
everything acting consistently.
Linting Within Your Editor#
If you are using an editor designed for Python development many of these code linting and formatting tools can be run automatically in the background while you write code or documentation. Popular editors that work with the above tools include:
Visual Studio Code, from Microsoft (free)
Atom developed by GitHub (free), and
Sublime Text (paid).
Each of these editors have their own collection of plugins and settings for working with linters and other code analysis tools.
Creating a Workspace#
PUDL Workspace Setup#
If you used
pudl_setup to set up your pudl workspace already,
skip ahead to PUDL Workspace Setup (legacy method). If you haven’t setup
a PUDL workspace before, read the remainder of this section.
PUDL needs to know where to store its big piles of inputs and outputs.
PUDL_INPUT environment variables let PUDL know where
all this stuff should go. We call this a “PUDL workspace”.
First, create a directory to store local caches of raw PUDL data. You can put
this anywhere, but we put this in
~/pudl_input in the documentation.
Then create an environment variable called
PUDL_INPUT to store the path to
this new directory:
$ echo "export PUDL_INPUT=/absolute/path/to/pudl_input" >> ~/.zshrc # if you are using zsh $ echo "export PUDL_INPUT=/absolute/path/to/pudl_input" >> ~/.bashrc # if you are using bash $ set -Ux PUDL_INPUT /absolute/path/to/pudl_input # if you are using fish shell
The directory stored in
PUDL_INPUT contains versions of PUDL’s
raw data archives on Zenodo for each datasource:
pudl_input/ ├── ferc1/ │ ├── 10.5281-zenodo.5534788/ │ │ ├── datapackage.json │ │ ├── ferc1-1994.zip │ │ ├── ferc1-1995.zip │ │ └── ... │ ├── 10.5281-zenodo.7314437/ │ │ └── ... │ └── ... ├── eia860/ │ └── ... └── ...
The data stored at the
PUDL_INPUT directory can grow to be dozens
of gigabytes in size. This is because when the raw data are updated,
a new version of the archive is downloaded to the
directory. To slim down the size you can always delete
out of date archives the code no longer depends on.
Next, create a directory to store the outputs of the PUDL ETL. As above, you
can put this anywhere, but typically this is
~/pudl_output. Then, as
PUDL_INPUT, create an environment variable called
store the path to this new directory:
$ echo "export PUDL_OUTPUT=/absolute/path/to/pudl_output" >> ~/.zshrc # zsh $ echo "export PUDL_OUTPUT=/absolute/path/to/pudl_output" >> ~/.bashrc # bash $ set -Ux PUDL_OUTPUT /absolute/path/to/pudl_output # fish
The path stored in
PUDL_OUTPUT contains all ETL outputs like
Make sure you create separate directories for these environment variables! It is recommended you create these directories outside of the pudl repository directory so the inputs and outputs are not tracked in git.
PUDL Workspace Setup (legacy method)#
In previous versions of PUDL, the
pudl_setup script created workspace directories.
PUDL is moving towards using the
variables instead of the
pudl_setup script because the environment variables are
easier to reference in the codebase.
If you set up your workspace using
pudl_setup you don’t need to change
anything about your setup. Just re-run
pudl_setup and a new directory
output/ will be created in your <PUDL_DIR>. You will need to
PUDL_OUTPUT at this new directory and
PUDL_INPUT at the
data/ directory in <PUDL_DIR>.
In a future release the
pudl_setup command will be removed.
pudl_setup script lets PUDL know where to store inputs and outputs.
The script will not create a new directory based on your arguemnts, so make
sure whatever directory path you pass as <PUDL_DIR> already exists.
$ pudl_setup <PUDL_DIR>
<PUDL_DIR> is the path to the directory where you want PUDL to do its
business – this is where the datastore will be located and where any outputs
that are generated end up. The script will also put a configuration file called
.pudl.yml in your home directory that records the location of this
workspace and uses it by default in the future. If you run
no arguments, it assumes you want to use the current working directory.
The workspace is laid out like this:
Directory / File
Raw data, automatically organized by source, year, etc.
This is the path
Apache Parquet files generated by PUDL.
Example configuration files for controlling PUDL scripts.