This is not a real parser, but an example template on how to write one. You can fork this repository to create actual parsers.

Get started

You should create a virtual environment. This is optional, but highly recommended as the required nomad-lab pypi package requires many dependencies with specific versions that might conflict with other libraries that you have installed. This was tested with Python 3.7.

pip install virtualenv
virtualenv -p `which python3` .pyenv
source .pyenv/bin/activate

Simply install our pypi package with pip:

pip install --upgrade pip
pip install nomad-lab

Clone this project (or fork and then clone the fork). Go into the cloned directly and directly run the parser from there:

git clone https://github.com/nomad-coe/nomad-parser-example.git parser-example
cd parser-example
python -m exampleparser tests/data/example.out

There are also a basic test framework written in pytest. Install the remaining dev dependencies and run the tests with:

pip install -r requirements.txt
pytest -sv tests

Next steps

Our documentation provides several resources that might be interesting:

• How to write a parser. Provides a more detailed tutorial on how to write a parser.
• Introduction to the NOMAD Metainfo. This explains how NOMAD data schema and can be extended and used within your parser.

To get you parser included in NOMAD or ask further questions, you can:

• Use our forums at matsci.org
• Open an issue on the example-parser GitHub project
• Write to [email protected]

Note! The rest of this README.md is the usual text that applies to all NOMAD parsers.

This is a NOMAD parser for EXAMPLE. It will read EXAMPLE input and output files and provide all information in NOMAD's unified Metainfo based Archive format.

Preparing code input and output file for uploading to NOMAD

NOMAD accepts .zip and .tar.gz archives as uploads. Each upload can contain arbitrary files and directories. NOMAD will automatically try to choose the right parser for you files. For each parser (i.e. for each supported code) there is one type of file that the respective parser can recognize. We call these files mainfiles as they typically are the main output file a code. For each mainfile that NOMAD discovers it will create an entry in the database that users can search, view, and download. NOMAD will associate all files in the same directory as files that also belong to that entry. Parsers might also read information from these auxillary files. This way you can add more files to an entry, even if the respective parser/code might not directly support it.

For EXAMPLE please provide at least the files from this table if applicable to your calculations (remember that you can provide more files if you want):

Input Filename	Description
example.out	Mainfile in EXAMPLE specific plain-text

To create an upload with all calculations in a directory structure:

zip -r <upload-file>.zip <directory>/*

Go to the NOMAD upload page to upload files or find instructions about how to upload files from the command line.

Using the parser

You can use NOMAD's parsers and normalizers locally on your computer. You need to install NOMAD's pypi package:

pip install nomad-lab

To parse code input/output from the command line, you can use NOMAD's command line interface (CLI) and print the processing results output to stdout:

nomad parse --show-archive <path-to-file>

To parse a file in Python, you can program something like this:

import sys
from nomad.cli.parse import parse, normalize_all

# match and run the parser
archive = parse(sys.argv[1])
# run all normalizers
normalize_all(archive)

# get the 'main section' section_run as a metainfo object
section_run = archive.section_run[0]

# get the same data as JSON serializable Python dict
python_dict = section_run.m_to_dict()

Developing the parser

Create a virtual environment to install the parser in development mode:

pip install virtualenv
virtualenv -p `which python3` .pyenv
source .pyenv/bin/activate

Install NOMAD's pypi package:

pip install nomad-lab

Clone the parser project and install it in development mode:

git clone https://github.com/nomad-coe/nomad-parser-example.git parser-example
pip install -e parser-example

Running the parser now, will use the parser's Python code from the clone project.

$parserSpecific$