satpy.cf.attrs module

CF processing of attributes.

class satpy.cf.attrs.AttributeEncoder(*, skipkeys=False, ensure_ascii=True, check_circular=True, allow_nan=True, sort_keys=False, indent=None, separators=None, default=None)

Bases: JSONEncoder

JSON encoder for dataset attributes.

Constructor for JSONEncoder, with sensible defaults.

If skipkeys is false, then it is a TypeError to attempt encoding of keys that are not str, int, float or None. If skipkeys is True, such items are simply skipped.

If ensure_ascii is true, the output is guaranteed to be str objects with all incoming non-ASCII characters escaped. If ensure_ascii is false, the output can contain non-ASCII characters.

If check_circular is true, then lists, dicts, and custom encoded objects will be checked for circular references during encoding to prevent an infinite recursion (which would cause an RecursionError). Otherwise, no such check takes place.

If allow_nan is true, then NaN, Infinity, and -Infinity will be encoded as such. This behavior is not JSON specification compliant, but is consistent with most JavaScript based encoders and decoders. Otherwise, it will be a ValueError to encode such floats.

If sort_keys is true, then the output of dictionaries will be sorted by key; this is useful for regression tests to ensure that JSON serializations can be compared on a day-to-day basis.

If indent is a non-negative integer, then JSON array elements and object members will be pretty-printed with that indent level. An indent level of 0 will only insert newlines. None is the most compact representation.

If specified, separators should be an (item_separator, key_separator) tuple. The default is (’, ‘, ‘: ‘) if indent is None and (‘,’, ‘: ‘) otherwise. To get the most compact JSON representation, you should specify (‘,’, ‘:’) to eliminate whitespace.

If specified, default is a function that gets called for objects that can’t otherwise be serialized. It should return a JSON encodable version of the object or raise a TypeError.

_encode(obj)

Encode the given object as a json-serializable datatype.

default(obj)

Return a json-serializable object for obj.

In order to facilitate decoding, elements in dictionaries, lists/tuples and multi-dimensional arrays are encoded recursively.

satpy.cf.attrs._add_ancillary_variables_attrs(data_arr: DataArray) → None

Replace ancillary_variables DataArray with a list of their name.

satpy.cf.attrs._add_history(attrs)

Add ‘history’ attribute to dictionary.

satpy.cf.attrs._drop_attrs(data_arr: DataArray, user_excluded_attrs: list[str] | None) → None

Remove undesirable attributes.

satpy.cf.attrs._encode_numpy_array(obj)

Encode numpy array as a netCDF4 serializable datatype.

satpy.cf.attrs._encode_object(obj)

Try to encode obj as a netCDF/Zarr compatible datatype which most closely resembles the object’s nature.

Raises:

ValueError if no such datatype could be found –

satpy.cf.attrs._encode_python_objects(obj)

Try to find the datatype which most closely resembles the object’s nature.

If on failure, encode as a string. Plain lists are encoded recursively.

satpy.cf.attrs._encode_to_cf(obj)

Encode the given object as a netcdf compatible datatype.

satpy.cf.attrs._format_prerequisites_attrs(data_arr: DataArray) → None

Reformat prerequisites attribute value to string.

satpy.cf.attrs._get_none_attrs(data_arr: DataArray) → list[str]

Remove attribute keys with None value.

satpy.cf.attrs._get_satpy_attrs(data_arr: DataArray) → list[str]

Remove _satpy attribute.

satpy.cf.attrs._try_decode_object(obj)

Try to decode byte string.

satpy.cf.attrs.encode_attrs_to_cf(attrs)

Encode dataset attributes as a netcdf compatible datatype.

Parameters:

attrs (dict) – Attributes to be encoded

Returns:

Encoded (and sorted) attributes

Return type:

dict

satpy.cf.attrs.preprocess_attrs(data_arr: DataArray, flatten_attrs: bool, exclude_attrs: list[str] | None) → DataArray

Preprocess DataArray attributes to be written into CF-compliant netCDF/Zarr.

satpy.cf.attrs.preprocess_header_attrs(header_attrs, flatten_attrs=False)

Prepare file header attributes.