FitsExposureFormatter¶

class lsst.obs.base.formatters.fitsExposure.FitsExposureFormatter(fileDescriptor: FileDescriptor, dataId: DataCoordinate, writeParameters: Optional[Dict[str, Any]] = None, writeRecipes: Optional[Dict[str, Any]] = None)¶

Bases: lsst.obs.base.formatters.fitsExposure.FitsImageFormatterBase

Specialization for Exposure reading.

Attributes Summary

`dataId`	Return Data ID associated with this formatter (`DataCoordinate`).
`extension`
`fileDescriptor`	File descriptor associated with this formatter (`FileDescriptor`).
`metadata`	The metadata read from this file.
`supportedExtensions`
`supportedWriteParameters`
`unsupportedParameters`
`writeParameters`	Parameters to use when writing out datasets.
`writeRecipes`	Detailed write Recipes indexed by recipe name.

Methods Summary

`can_read_bytes`()	Indicate if this formatter can format from bytes.
`fromBytes`(serializedDataset, component)	Read serialized data into a Dataset or its component.
`getImageCompressionSettings`(recipeName)	Retrieve the relevant compression settings for this recipe.
`makeUpdatedLocation`(location)	Return a new `Location` updated with this formatter’s extension.
`name`()	Return the fully qualified name of the formatter.
`predictPath`()	Return the path that would be returned by write.
`read`([component])	Read data from a file.
`readComponent`(component[, parameters])	Read a component held by the Exposure.
`readFull`([parameters])	Read the full Exposure object.
`readMetadata`()	Read all header metadata directly into a PropertyList.
`segregateParameters`(parameters, Any]] = None)	Segregate the supplied parameters.
`stripMetadata`()	Remove metadata entries that are parsed into components.
`toBytes`(inMemoryDataset)	Serialize the Dataset to bytes based on formatter.
`validateExtension`(location)	Check the extension of the provided location for compatibility.
`validateWriteRecipes`(recipes)	Validate supplied recipes for this formatter.
`write`(inMemoryDataset)	Write a Python object to a file.

Attributes Documentation

dataId¶: Return Data ID associated with this formatter (DataCoordinate).

extension = '.fits'¶

fileDescriptor¶

File descriptor associated with this formatter (FileDescriptor).

Read-only property.

metadata¶: The metadata read from this file. It will be stripped as components are extracted from it (lsst.daf.base.PropertyList).

supportedExtensions = frozenset({'.fits.fz', '.fits.gz', '.fz', '.fits', '.fit'})¶

supportedWriteParameters = frozenset({'recipe'})¶

unsupportedParameters = {}¶

writeParameters¶: Parameters to use when writing out datasets.

writeRecipes¶: Detailed write Recipes indexed by recipe name.

Methods Documentation

classmethod can_read_bytes() → bool¶

Indicate if this formatter can format from bytes.

Returns:	can : `bool` `True` if the `fromBytes` method is implemented.

fromBytes(serializedDataset: bytes, component: Optional[str] = None) → object¶

Read serialized data into a Dataset or its component.

Parameters:	serializedDataset : `bytes` Bytes object to unserialize. component : `str`, optional Component to read from the Dataset. Only used if the `StorageClass` for reading differed from the `StorageClass` used to write the file.
Returns:	inMemoryDataset : `object` The requested data as a Python object. The type of object is controlled by the specific formatter.

getImageCompressionSettings(recipeName)¶

Retrieve the relevant compression settings for this recipe.

Parameters:	recipeName : `str` Label associated with the collection of compression parameters to select.
Returns:	settings : `dict` The selected settings.

makeUpdatedLocation(location: lsst.daf.butler.core.location.Location) → lsst.daf.butler.core.location.Location¶

Return a new Location updated with this formatter’s extension.

Parameters:	location : `Location` The location to update.
Returns:	updated : `Location` A new `Location` with a new file extension applied.
Raises:	NotImplementedError Raised if there is no `extension` attribute associated with this formatter.

Notes

This method is available to all Formatters but might not be implemented by all formatters. It requires that a formatter set an extension attribute containing the file extension used when writing files. If extension is None the supplied file will not be updated. Not all formatters write files so this is not defined in the base class.

classmethod name() → str¶

Return the fully qualified name of the formatter.

Returns:	name : `str` Fully-qualified name of formatter class.

predictPath() → str¶

Return the path that would be returned by write.

Does not write any data file.

Uses the FileDescriptor associated with the instance.

Returns:	path : `str` Path within datastore that would be associated with the location stored in this `Formatter`.

read(component=None)¶

Read data from a file.

Parameters:	component : `str`, optional Component to read from the file. Only used if the `StorageClass` for reading differed from the `StorageClass` used to write the file.
Returns:	inMemoryDataset : `object` The requested data as a Python object. The type of object is controlled by the specific formatter.
Raises:	ValueError Component requested but this file does not seem to be a concrete composite. KeyError Raised when parameters passed with fileDescriptor are not supported.

readComponent(component, parameters=None)¶

Read a component held by the Exposure.

Parameters:	component : `str`, optional Component to read from the file. parameters : `dict`, optional If specified, a dictionary of slicing parameters that overrides those in `fileDescriptor`.
Returns:	obj : component-dependent In-memory component object.
Raises:	KeyError Raised if the requested component cannot be handled.

readFull(parameters=None)¶

Read the full Exposure object.

Parameters:	parameters : `dict`, optional If specified a dictionary of slicing parameters that overrides those in `fileDescriptor`.
Returns:	exposure : `Exposure` Complete in-memory exposure.

readMetadata()¶

Read all header metadata directly into a PropertyList.

Returns:	metadata : `PropertyList` Header metadata.

segregateParameters(parameters: Optional[Dict[str, Any]] = None) → Tuple[Dict[KT, VT], Dict[KT, VT]]¶

Segregate the supplied parameters.

This splits the parameters into those understood by the formatter and those not understood by the formatter.

Any unsupported parameters are assumed to be usable by associated assemblers.

Parameters:	parameters : `dict`, optional Parameters with values that have been supplied by the caller and which might be relevant for the formatter. If `None` parameters will be read from the registered `FileDescriptor`.
Returns:	supported : `dict` Those parameters supported by this formatter. unsupported : `dict` Those parameters not supported by this formatter.

stripMetadata()¶

Remove metadata entries that are parsed into components.

This is only called when just the metadata is requested; stripping entries there forces code that wants other components to ask for those components directly rather than trying to extract them from the metadata manually, which is fragile. This behavior is an intentional change from Gen2.

Parameters:	metadata : `PropertyList` Header metadata, to be modified in-place.

toBytes(inMemoryDataset: Any) → bytes¶

Serialize the Dataset to bytes based on formatter.

Parameters:	inMemoryDataset : `object` The Python object to serialize.
Returns:	serializedDataset : `bytes` Bytes representing the serialized dataset.

classmethod validateExtension(location: lsst.daf.butler.core.location.Location) → None¶

Check the extension of the provided location for compatibility.

Parameters:	location : `Location` Location from which to extract a file extension.
Raises:	NotImplementedError Raised if file extensions are a concept not understood by this formatter. ValueError Raised if the formatter does not understand this extension.

Notes

This method is available to all Formatters but might not be implemented by all formatters. It requires that a formatter set an extension attribute containing the file extension used when writing files. If extension is None only the set of supported extensions will be examined.

classmethod validateWriteRecipes(recipes)¶

Validate supplied recipes for this formatter.

The recipes are supplemented with default values where appropriate.

TODO: replace this custom validation code with Cerberus (DM-11846)

Parameters:	recipes : `dict` Recipes to validate. Can be empty dict or `None`.
Returns:	validated : `dict` Validated recipes. Returns what was given if there are no recipes listed.
Raises:	RuntimeError Raised if validation fails.

write(inMemoryDataset)¶

Write a Python object to a file.

Parameters:	inMemoryDataset : `object` The Python object to store.

Navigation

FitsExposureFormatter¶