Source code for satpy._scene_converters

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"""Helper functions for converting the Scene object to some other object."""

import xarray as xr

from satpy.dataset import DataID


[docs] def _get_dataarrays_from_identifiers(scn, identifiers): """Return a list of DataArray based on a single or list of identifiers. An identifier can be a DataID or a string with name of a valid DataID. """ if isinstance(identifiers, (str, DataID)): identifiers = [identifiers] if identifiers is not None: dataarrays = [scn[ds] for ds in identifiers] else: dataarrays = [scn._datasets.get(ds) for ds in scn._wishlist] dataarrays = [dataarray for dataarray in dataarrays if dataarray is not None] return dataarrays
[docs] def to_xarray(scn, datasets=None, # DataID header_attrs=None, exclude_attrs=None, flatten_attrs=False, pretty=True, include_lonlats=True, epoch=None, include_orig_name=True, numeric_name_prefix='CHANNEL_'): """Merge all xr.DataArray(s) of a satpy.Scene to a CF-compliant xarray object. If all Scene DataArrays are on the same area, it returns an xr.Dataset. If Scene DataArrays are on different areas, currently it fails, although in future we might return a DataTree object, grouped by area. Parameters ---------- scn: satpy.Scene Satpy Scene. datasets (iterable): List of Satpy Scene datasets to include in the output xr.Dataset. Elements can be string name, a wavelength as a number, a DataID, or DataQuery object. If None (the default), it include all loaded Scene datasets. header_attrs: Global attributes of the output xr.Dataset. epoch (str): Reference time for encoding the time coordinates (if available). Example format: "seconds since 1970-01-01 00:00:00". If None, the default reference time is retrieved using "from satpy.cf_writer import EPOCH" flatten_attrs (bool): If True, flatten dict-type attributes. exclude_attrs (list): List of xr.DataArray attribute names to be excluded. include_lonlats (bool): If True, it includes 'latitude' and 'longitude' coordinates. If the 'area' attribute is a SwathDefinition, it always includes latitude and longitude coordinates. pretty (bool): Don't modify coordinate names, if possible. Makes the file prettier, but possibly less consistent. include_orig_name (bool). Include the original dataset name as a variable attribute in the xr.Dataset. numeric_name_prefix (str): Prefix to add the each variable with name starting with a digit. Use '' or None to leave this out. Returns ------- ds, xr.Dataset A CF-compliant xr.Dataset """ from satpy.writers.cf_writer import EPOCH, collect_cf_datasets if epoch is None: epoch = EPOCH # Get list of DataArrays if datasets is None: datasets = list(scn.keys()) # list all loaded DataIDs list_dataarrays = _get_dataarrays_from_identifiers(scn, datasets) # Check that some DataArray could be returned if len(list_dataarrays) == 0: return xr.Dataset() # Collect xr.Dataset for each group grouped_datasets, header_attrs = collect_cf_datasets(list_dataarrays=list_dataarrays, header_attrs=header_attrs, exclude_attrs=exclude_attrs, flatten_attrs=flatten_attrs, pretty=pretty, include_lonlats=include_lonlats, epoch=epoch, include_orig_name=include_orig_name, numeric_name_prefix=numeric_name_prefix, groups=None) if len(grouped_datasets) == 1: ds = grouped_datasets[None] return ds else: msg = """The Scene object contains datasets with different areas. Resample the Scene to have matching dimensions using i.e. scn.resample(resampler="native") """ raise NotImplementedError(msg)