Source code for openghg.retrieve.ceda._retrieve
from typing import Any
from openghg.dataobjects import ObsData
from openghg.objectstore import get_writable_bucket
import logging
logger = logging.getLogger("openghg.retrieve")
logger.setLevel(logging.DEBUG) # Have to set level for logger as well as handler
[docs]
def retrieve_surface(
site: str | None = None,
species: str | None = None,
inlet: str | None = None,
url: str | None = None,
force_retrieval: bool = False,
additional_metadata: dict | None = None,
store: str | None = None,
) -> list[ObsData] | ObsData | None:
"""Retrieve surface measurements from the CEDA archive. This function will route the call
to either local or cloud functions based on the environment.
Args:
site: Site name
species: Species name
inlet: Inlet height
url: URL of data in CEDA archive
force_retrieval: Force the retrieval of data from a URL
additional_metadata: Additional metadata to pass if the returned data
doesn't contain everythging we need. At the moment we try and find site and inlet
keys if they aren't found in the dataset's attributes.
For example:
{"site": "AAA", "inlet": "10m"}
store: Name of object store to use
Returns:
ObsData or None: ObsData if data found / retrieved successfully.
Example:
To retrieve new data from the CEDA archive using a URL
>>> retrieve_surface(url=https://dap.ceda.ac.uk/badc/...)
To retrieve already cached data from the object store
>>> retrieve_surface(site="BSD", species="ch4)
"""
return retrieve(
site=site,
species=species,
inlet=inlet,
url=url,
force_retrieval=force_retrieval,
additional_metadata=additional_metadata,
store=store,
)
def retrieve(
site: str | None = None,
species: str | None = None,
inlet: str | None = None,
url: str | None = None,
force_retrieval: bool = False,
additional_metadata: dict | None = None,
store: str | None = None,
**kwargs: Any,
) -> list[ObsData] | ObsData | None:
"""Retrieve surface observations data from the CEDA archive. You can pass
search terms and the object store will be searched. To retrieve data from the
CEDA Archive please browse the website (https://data.ceda.ac.uk/badc) to find
the URL of the dataset to retrieve.
Args:
site: Site name
species: Species name
inlet: Inlet height
url: URL of data in CEDA archive
force_retrieval: Force the retrieval of data from a URL
additional_metadata: Additional metadata to pass if the returned data
doesn't contain everythging we need. At the moment we try and find site and inlet
keys if they aren't found in the dataset's attributes.
For example:
{"site": "AAA", "inlet": "10m"}
store: Name of object store
Returns:
ObsData or None: ObsData if data found / retrieved successfully.
Example:
To retrieve new data from the CEDA archive using a URL
>>> retrieve_surface(url=https://dap.ceda.ac.uk/badc/...)
To retrieve already cached data from the object store
>>> retrieve_surface(site="BSD", species="ch4)
"""
import io
import xarray as xr
from openghg.retrieve import search_surface
from openghg.store import ObsSurface
from openghg.util import download_data, parse_url_filename, site_code_finder, timestamp_now
if additional_metadata is None:
additional_metadata = {}
results = search_surface(site=site, species=species, inlet=inlet, data_source="ceda_archive", store=store)
if results and not force_retrieval or url is None:
return results.retrieve_all()
filename = parse_url_filename(url=url)
extension = filename.split(".")[-1].lower()
if extension != "nc":
logger.warning("We can only currently retrieve and process NetCDF files.")
return None
binary_data = download_data(url=url)
if binary_data is None:
logger.error("No data retrieved.")
return None
with io.BytesIO(binary_data) as buf:
# Type ignored as buf is file-like which should be accepted by xarray
# open_dataset - https://docs.xarray.dev/en/stable/generated/xarray.open_dataset.html
# 27/07/2022: file-like (including BytesIO) isn't included in the accepted types
# - Union[str, PathLike[Any], AbstractDataStore]
dataset = xr.open_dataset(buf).load() # type:ignore
now = str(timestamp_now())
key = f"{filename}_{now}"
# We expect to be dealing with timeseries data here
# We'll take the attributes as metadata
metadata = dataset.attrs.copy()
metadata["data_type"] = "surface"
metadata["data_source"] = "ceda_archive"
# TODO - how should we find these? Need to change how we're retrieving Datasources
# using metadata
metadata["network"] = metadata.get("network", "CEDA_RETRIEVED")
metadata["sampling_period"] = metadata.get("sampling_period", "NA")
# If we're going to be using site, species and inlet here we should check that that
# information is in the metadata
if not {"site", "inlet"} <= metadata.keys():
site_name = metadata["station_long_name"]
site_code = site_code_finder(site_name=site_name)
if site_code is not None:
metadata["site"] = site_code
else:
if additional_metadata:
try:
metadata["site"] = additional_metadata["site"]
except KeyError:
logger.error("Unable to read site from additional_metadata.")
return None
else:
logger.error("Error: cannot find site code, please pass additional metadata.")
return None
try:
metadata["inlet"] = f"{int(metadata['inlet_height_magl'])}m"
except KeyError:
try:
metadata["inlet"] = additional_metadata["inlet"]
except KeyError:
logger.error("Unable to read inlet from data or additional_metadata.")
return None
to_store = {key: {"data": dataset, "metadata": metadata}}
bucket = get_writable_bucket(name=store)
with ObsSurface(bucket=bucket) as obs:
obs.store_data(data=to_store)
return ObsData(data=dataset, metadata=metadata)
