openeo-pg-parser-networkx 2022.12.1

Parse OpenEO process graphs from JSON to traversible Python objects.

OpenEO Process Graph Parser (Python & networkx)

Python package to parse OpenEO process graphs from raw JSON into fully traversible networkx graph objects. This package is an evolution of the openeo-pg-parser-python package.

Installation

This package can be installed with pip:

pip install openeo-pg-parser-networkx

Currently Python versions 3.9 and 3.10 are supported.

Basic usage

(An example notebook of using openeo-pg-parser-networkx together with a process implementation source like openeo-processes-dask can be found in openeo-pg-parser-networkx/examples/01_minibackend_demo.ipynb.)

Parse a JSON OpenEO process graph:

from openeo_pg_parser_networkx.graph import OpenEOProcessGraph

NDVI_GRAPH_PATH = "../tests/data/graphs/apply.json"

parsed_graph = OpenEOProcessGraph.from_file(NDVI_GRAPH_PATH)

> Deserialised process graph into nested structure
> Walking node root-fd8ae3b4-8cb8-46c8-a5cd-c8ee552d1945
> Walking node apply2-fd8ae3b4-8cb8-46c8-a5cd-c8ee552d1945
> Walking node multiply1-f8644201-32a8-4283-8814-a577c4e28226
> Walking node apply1-fd8ae3b4-8cb8-46c8-a5cd-c8ee552d1945
> Walking node ndvi1-06a8d8af-296a-4960-a1cb-06dcd251b6bb
> Walking node loadcollection1-fd8ae3b4-8cb8-46c8-a5cd-c8ee552d1945

Plot it:

parsed_graph.plot()

To execute a process graph, OpenEOProcessGraph needs to know which Python code to call for each of the nodes in the graph. This information is provided by a "process registry", which is basically a dictionary that maps each process_id to its actual Python implementation as a Callable.

Register process implementations to a "process registry":

from openeo_pg_parser_networkx import ProcessRegistry
process_registry = ProcessRegistry()

from openeo_processes_dask.process_implementations import apply, ndvi, multiply, load_collection, save_result

process_registry["apply"] =  apply
process_registry["ndvi"] =  ndvi
process_registry["multiply"] =  multiply
process_registry["load_collection"] =  load_collection
process_registry["save_result"] =  save_result

Build an executable callable from the process graph:

pg_callable = parsed_graph.to_callable(process_registry=process_registry)

Execute that callable like a normal Python function:

pg_callable

> Running process load_collection
> Running process apply
> ...

Development environment

openeo-pg-parser-networkx requires poetry >1.2, see their docs for installation instructions.

To setup the python venv and install this project into it run:

poetry install

To add a new core dependency run:

poetry add some_new_dependency

To add a new development dependency run:

poetry add some_new_dependency --group dev

To run the test suite run:

poetry run python -m pytest

Note that you can also use the virtual environment that's generated by poetry as the kernel for the ipynb notebooks.

Pre-commit hooks

This repo makes use of pre-commit hooks to enforce linting & a few sanity checks. In a fresh development setup, install the hooks using poetry run pre-commit install. These will then automatically be checked against your changes before making the commit.