cads-api-client

cads-api-client

CADS API Python client

Technical documentation: https://ecmwf-projects.github.io/cads-api-client/

Configuration

The ApiClient requires the url to the API root and a valid API key. You can also set the CADS_API_URL and CADS_API_KEY environment variables, or use a configuration file. The configuration file must be located at ~/.cads-api-client.json, or at the path specified by the CADS_API_RC environment variable.

$ cat $HOME/.cads-api-client.json
{"url": "https://cds.climate.copernicus.eu/api", "key": "xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx"}

It is possible (though not recommended) to use the API key of one of the test users:

00112233-4455-6677-c899-aabbccddeeff

This key is used for anonymous tests and is designed to be the least performant option for accessing the system.

Quick Start

Configure the logging level to display INFO messages:

>>> import logging
>>> logging.basicConfig(level="INFO")

Instantiate the API client and verify the authentication:

>>> import os
>>> from cads_api_client import ApiClient
>>> client = ApiClient(
...     url=os.getenv("CADS_API_URL"),
...     key=os.getenv("CADS_API_KEY"),
... )
>>> client.check_authentication()
{...}

Explore a collection:

>>> collection_id = "reanalysis-era5-pressure-levels"
>>> collection = client.get_collection(collection_id)
>>> collection.end_datetime
datetime.datetime(...)

>>> request = {
...     "product_type": "reanalysis",
...     "variable": "temperature",
...     "year": "2022",
...     "month": "01",
...     "day": "01",
...     "pressure_level": "1000",
...     "time": "00:00",
... }
>>> collection.process.apply_constraints(**request)
{...}

Retrieve data:

>>> client.retrieve(collection_id, target="tmp1-era5.grib", **request)  # blocks
'tmp1-era5.grib'

>>> remote = client.submit(collection_id, **request)  # doesn't block
>>> remote.request_uid
'...'
>>> remote.status
'...'
>>> remote.download("tmp2-era5.grib")  # blocks
'tmp2-era5.grib'

Interact with a previously submitted job:

>>> remote = client.get_remote(remote.request_uid)
>>> remote.delete()
{...}

Workflow for developers/contributors

For best experience create a new conda environment (e.g. DEVELOP) with Python 3.11:

conda create -n DEVELOP -c conda-forge python=3.11
conda activate DEVELOP

Before pushing to GitHub, run the following commands:

1. Update conda environment: make conda-env-update
2. Install this package: pip install -e .
3. Sync with the latest template (optional): make template-update
4. Run quality assurance checks: make qa
5. Run tests: make unit-tests
6. Run the static type checker: make type-check
7. Build the documentation (see Sphinx tutorial): make docs-build

License

Copyright 2022, European Union.

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

    http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.