lsst.daf.butler

This module provides an abstracted data access interface, known as the Butler. It can be used to read and write data without having to know the details of file formats or locations.

Contributing

lsst.daf.butler is developed at https://github.com/lsst/daf_butler. You can find Jira issues for this module under the daf_butler component.

Using the Butler

• Configuring a Butler
• Organizing and identifying datasets
• Querying datasets
• Using the Butler in unit tests

Command Line Scripts

butler

butler [OPTIONS] COMMAND [ARGS]...

Options

--log-level <log_level>

The Python log level to use.

Options:critical|error|warning|info|debug|CRITICAL|ERROR|WARNING|INFO|DEBUG

config-dump

Dump either a subset or full Butler configuration to standard output.

REPO is the URI or path to an existing data repository root or configuration file.

butler config-dump [OPTIONS] REPO

Options

-s, --subset <subset>

Subset of a configuration to report. This can be any key in the hierarchy such as ‘.datastore.root’ where the leading ‘.’ specified the delimiter for the hierarchy.

-p, --searchpath <searchpath>

Additional search paths to use for configuration overrides

--file <outfile>

Print the (possibly-expanded) configuration for a repository to a file, or to stdout by default.

Arguments

REPO

Required argument

config-validate

Validate the configuration files for a Gen3 Butler repository.

REPO is the URI or path to an existing data repository root or configuration file.

butler config-validate [OPTIONS] REPO

Options

-q, --quiet

Do not report individual failures.

-d, --dataset-type <dataset_type>

Specific DatasetType(s) to validate.

-i, --ignore <ignore>

DatasetType(s) to ignore for validation.

Arguments

REPO

Required argument

create

Create an empty Gen3 Butler repository.

REPO is the URI or path to the new repository. Will be created if it does not exist.

butler create [OPTIONS] [REPO]

Options

-C, --config-file <config_file>

The path to the config file.

--standalone

Include all defaults in the config file in the repo, insulating the repo from changes in package defaults.

-o, --override

Allow values in the supplied config to override any repo settings.

-f, --outfile <outfile>

Name of output file to receive repository configuration. Default is to write butler.yaml into the specified repo.

Arguments

REPO

Optional argument

ingest-raws

REPO is the URI or path to an existing data repository root or configuration file.

butler ingest-raws [OPTIONS] REPO

Options

-c, --config <config>

Config override, as a key-value pair.

-C, --config-file <config_file>

The path to the config file.

--output-run <output_run>

The name of the run datasets should be output to. [required]

-d, --dir <directory>

The path to the directory containing the raws to ingest.

-f, --file <file>

The name of a file containing raws to ingest.

-t, --transfer <transfer>

The external data transfer type.

--ingest-task <ingest_task>

The fully qualified class name of the ingest task to use.

Arguments

REPO

Required argument

register-instrument

Add an instrument to the data repository.

REPO is the URI or path to an existing data repository root or configuration file.

butler register-instrument [OPTIONS] REPO

Options

-i, --instrument <instrument>

The fully-qualified name of an Instrument subclass. [required]

Arguments

REPO

Required argument

write-curated-calibrations

Add an instrument’s curated calibrations to the data repository.

REPO is the URI or path to an existing data repository root or configuration file.

butler write-curated-calibrations [OPTIONS] REPO

Options

-i, --instrument <instrument>

The name or fully-qualified class name of an instrument. [required]

--output-run <output_run>

The name of the run datasets should be output to. [required]

Arguments

REPO

Required argument

The Dimensions System

• Overview
• Dimension Relationships and Containers
• Data IDs
• Spatial and Temporal Dimensions

Concrete Storage Classes

• DataFrame

Python API reference

lsst.daf.butler Package

Functions

addDimensionForeignKey(tableSpec, dimension, …)	Add a field and possibly a foreign key to a table specification that reference the table for the given Dimension.
makeDimensionElementTableSpec(element)	Create a complete table specification for a DimensionElement.

Classes

AmbiguousDatasetError	Exception raised when a DatasetRef is not resolved (has no ID, run, or components), but the requested operation requires one of them.
Butler(config, str, None] = None, *, butler, …)	Main entry point for the data access system.
ButlerConfig([other, searchPaths])	Contains the configuration for a Butler
ButlerURI(uri[, root, forceAbsolute, …])	Convenience wrapper around URI parsers.
ButlerValidationError	There is a problem with the Butler configuration.
CollectionSearch(items, …)	An ordered search path of collections and dataset type restrictions.
CollectionType	Enumeration used to label different types of collections.
CompositeAssembler(storageClass)	Class for providing assembler and disassembler support for composites.
CompositesConfig([other, validate, …])
CompositesMap(config, *, universe)	Determine whether a specific datasetType or StorageClass should be disassembled.
Config([other])	Implements a datatype that is used by Butler for configuration parameters.
ConfigSubset([other, validate, …])	Config representing a subset of a more general configuration.
ConsistentDataIds(overlaps, contains, within)	A struct used to report relationships between data IDs by Registry.relateDataIds.
Constraints(config, str]], *, universe)	Determine whether a DatasetRef, DatasetType, or StorageClass is allowed to be handled.
ConstraintsConfig([other])	Configuration information for Constraints
ConstraintsValidationError	Exception thrown when a constraints list has mutually exclusive definitions.
DataCoordinate(graph, values, …])	An immutable data ID dictionary that guarantees that its key-value pairs identify all required dimensions in a DimensionGraph.
DatasetComponent(name, storageClass, component)	Component of a dataset and associated information.
DatasetRef	Reference to a Dataset in a Registry.
DatasetType(name, dimensions, …)	A named category of Datasets that defines how they are organized, related, and stored.
DatasetTypeNotSupportedError	A DatasetType is not handled by this routine.
DatasetTypeRestriction(names, ellipsis])	An immutable set-like object that represents a restriction on the dataset types to search for within a collection.
Datastore(config, str], bridgeManager, …)	Datastore interface.
DatastoreConfig([other, validate, …])
DatastoreValidationError	There is a problem with the Datastore configuration.
DeferredDatasetHandle(butler, ref, parameters)	Proxy class that provides deferred loading of a dataset from a butler.
Dimension(name, *, related, uniqueKeys, **kwargs)	A named data-organization concept that can be used as a key in a data ID.
DimensionConfig([other, validate, …])	Configuration that defines a DimensionUniverse.
DimensionElement(name, *, related, metadata, …)	A named data-organization concept that defines a label and/or metadata in the dimensions system.
DimensionGraph	An immutable, dependency-complete collection of dimensions.
DimensionPacker(fixed, dimensions)	An abstract base class for bidirectional mappings between a DataCoordinate and a packed integer ID.
DimensionRecord(*args)	Base class for the Python representation of database records for a DimensionElement.
DimensionUniverse	A special DimensionGraph that constructs and manages a complete set of compatible dimensions.
ExpandedDataCoordinate(graph, values, …], …)	A data ID that has been expanded to include all relevant metadata.
FileDataset(path, refs, List[DatasetRef]], …)	A struct that represents a dataset exported to a file.
FileDescriptor(location, storageClass, …)	Describes a particular file.
FileTemplate(template)	Format a path template into a fully expanded path.
FileTemplateValidationError	Exception thrown when a file template is not consistent with the associated DatasetType.
FileTemplates(config, str], default, *, universe)	Collection of FileTemplate templates.
FileTemplatesConfig([other])	Configuration information for FileTemplates
Formatter(fileDescriptor, dataId)	Interface for reading and writing Datasets with a particular StorageClass.
FormatterFactory()	Factory for Formatter instances.
IndexedTupleDict(indices, int][K, int], …)	An immutable mapping that combines a tuple of values with a (possibly shared) mapping from key to tuple index.
Location(datastoreRootUri, path)	Identifies a location within the Datastore.
LocationFactory(datastoreRoot)	Factory for Location instances.
LookupKey([name, dimensions, dataId, universe])	Representation of key that can be used to lookup information based on dataset type name, storage class name, dimensions.
MappingFactory(refType)	Register the mapping of some key to a python type and retrieve instances.
NamedKeyDict(*args)	A dictionary wrapper that require keys to have a .name attribute, and permits lookups using either key objects or their names.
NamedKeyMapping	An abstract base class for custom mappings whose keys are objects with a str name attribute, for which lookups on the name as well as the object are permitted.
NamedValueSet(elements)	A custom mutable set class that requires elements to have a .name attribute, which can then be used as keys in dict-like lookup.
Quantum(*, taskName, taskClass, dataId, run, …)	A discrete unit of work that may depend on one or more datasets and produces one or more datasets.
Registry(database, universe, *, opaque, …)	Registry interface.
RepoExport(registry, datastore, backend, *, …)	Public interface for exporting a subset of a data repository.
RepoExportBackend	An abstract interface for data repository export implementations.
RepoImportBackend	An abstract interface for data repository import implementations.
RepoTransferFormatConfig([other, validate, …])	The section of butler configuration that associates repo import/export backends with file formats.
SkyPixDimension(name, pixelization)	A special Dimension subclass for hierarchical pixelizations of the sky.
StorageClass(name, pytype, str, …)	Class describing how a label maps to a particular Python type.
StorageClassConfig([other, validate, …])
StorageClassFactory(config, str, None] = None)	Factory for StorageClass instances.
StoredDatastoreItemInfo	Internal information associated with a stored dataset in a Datastore.
StoredFileInfo(formatter, …)	Datastore-private metadata associated with a file stored in a Datastore.
Timespan	A generic 2-element named tuple for time intervals.
ValidationError	Some sort of validation error has occurred.
YamlRepoExportBackend(stream)	A repository export implementation that saves to a YAML file.
YamlRepoImportBackend(stream, registry)	A repository import implementation that reads from a YAML file.

Class Inheritance Diagram

lsst.daf.butler.registry Package

Classes

CollectionSearch(items, …)	An ordered search path of collections and dataset type restrictions.
CollectionType	Enumeration used to label different types of collections.
ConflictingDefinitionError	Exception raised when trying to insert a database record when a conflicting record already exists.
ConsistentDataIds(overlaps, contains, within)	A struct used to report relationships between data IDs by Registry.relateDataIds.
DatasetTypeRestriction(names, ellipsis])	An immutable set-like object that represents a restriction on the dataset types to search for within a collection.
DbAuth([path, envVar, authList])	Retrieves authentication information for database connections.
DbAuthError	A problem has occurred retrieving database authentication information.
DbAuthPermissionsError	Credentials file has incorrect permissions.
InconsistentDataIdError	Exception raised when a data ID contains contradictory key-value pairs, according to dimension relationships.
MissingCollectionError	Exception raised when an operation attempts to use a collection that does not exist.
OrphanedRecordError	Exception raised when trying to remove or modify a database record that is still being used in some other table.
Registry(database, universe, *, opaque, …)	Registry interface.
RegistryConfig([other, validate, …])

Class Inheritance Diagram

lsst.daf.butler.registry.interfaces Package

Classes

ChainedCollectionRecord(key, name)	A subclass of CollectionRecord that adds the list of child collections in a CHAINED collection.
CollectionManager	An interface for managing the collections (including runs) in a Registry.
CollectionRecord(key, name, type)	A struct used to represent a collection in internal Registry APIs.
Database(*, origin, connection, namespace)	An abstract interface that represents a particular database engine’s representation of a single schema/namespace/database.
DatabaseConflictError	Exception raised when database content (row values or schema entities) are inconsistent with what this client expects.
DatasetRecordStorage(datasetType)	An interface that manages the records associated with a particular DatasetType.
DatasetRecordStorageManager	An interface that manages the tables that describe datasets.
DatastoreRegistryBridge(datastoreName)	An abstract base class that defines the interface that a Datastore uses to communicate with a Registry.
DatastoreRegistryBridgeManager(*, opaque, …)	An abstract base class that defines the interface between Registry and Datastore when a new Datastore is constructed.
DimensionRecordStorage	An abstract base class that represents a way of storing the records associated with a single DimensionElement.
DimensionRecordStorageManager(*, universe)	An interface for managing the dimension records in a Registry.
FakeDatasetRef	A fake DatasetRef that can be used internally by butler where only the dataset ID is available.
MissingCollectionError	Exception raised when an operation attempts to use a collection that does not exist.
OpaqueTableStorage(name)	An interface that manages the records associated with a particular opaque table in a Registry.
OpaqueTableStorageManager	An interface that manages the opaque tables in a Registry.
ReadOnlyDatabaseError	Exception raised when a write operation is called on a read-only Database.
RunRecord(key, name, type)	A subclass of CollectionRecord that adds execution information and an interface for updating it.
StaticTablesContext(db)	Helper class used to declare the static schema for a registry layer in a database.

Class Inheritance Diagram

lsst.daf.butler.registry.queries Package

Classes

Query(*, sql, summary, columns, collections)	A wrapper for a SQLAlchemy query that knows how to transform result rows into data IDs and dataset references.
QueryBuilder(summary, *, collections, …)	A builder for potentially complex queries that join tables based on dimension relationships.
QuerySummary(requested, *, dataId, …)	A struct that holds and categorizes the dimensions involved in a query.

Class Inheritance Diagram

lsst.daf.butler.registry.wildcards Module

Classes

CategorizedWildcard(strings, patterns, …)	The results of preprocessing a wildcard expression to separate match patterns from strings.
CollectionQuery(search, ellipsis], patterns, …)	An unordered query for collections and dataset type restrictions.
CollectionSearch(items, …)	An ordered search path of collections and dataset type restrictions.
DatasetTypeRestriction(names, ellipsis])	An immutable set-like object that represents a restriction on the dataset types to search for within a collection.

Class Inheritance Diagram

Example datastores

lsst.daf.butler.datastores.posixDatastore Module

Classes

PosixDatastore(config, str], bridgeManager, …)

Basic POSIX filesystem backed Datastore.

Class Inheritance Diagram

lsst.daf.butler.datastores.inMemoryDatastore Module

Classes

StoredMemoryItemInfo(timestamp, …)	Internal InMemoryDatastore Metadata associated with a stored DatasetRef.
InMemoryDatastore(config, str], …)	Basic Datastore for writing to an in memory cache.

Class Inheritance Diagram

lsst.daf.butler.datastores.chainedDatastore Module

Classes

ChainedDatastore(config, str], …)

Chained Datastores to allow read and writes from multiple datastores.

Class Inheritance Diagram

Example formatters

lsst.daf.butler.formatters.fileFormatter Module

Classes

FileFormatter(fileDescriptor, dataId)

Interface for reading and writing files on a POSIX file system.

Class Inheritance Diagram

lsst.daf.butler.formatters.jsonFormatter Module

Classes

JsonFormatter(fileDescriptor, dataId)

Interface for reading and writing Python objects to and from JSON files.

Class Inheritance Diagram

lsst.daf.butler.formatters.yamlFormatter Module

Classes

YamlFormatter(fileDescriptor, dataId)

Interface for reading and writing Python objects to and from YAML files.

Class Inheritance Diagram

lsst.daf.butler.formatters.pickleFormatter Module

Classes

PickleFormatter(fileDescriptor, dataId)

Interface for reading and writing Python objects to and from pickle files.

Class Inheritance Diagram

Database backends

lsst.daf.butler.registry.databases.sqlite Module

Classes

SqliteDatabase(*, connection, origin, …)

An implementation of the Database interface for SQLite3.

Class Inheritance Diagram

lsst.daf.butler.registry.databases.postgresql Module

Classes

PostgresqlDatabase(*, connection, origin, …)

An implementation of the Database interface for PostgreSQL.

Class Inheritance Diagram

lsst.daf.butler.registry.databases.oracle Module

Classes

OracleDatabase(*, connection, origin, …)

An implementation of the Database interface for Oracle.

Class Inheritance Diagram

Support API

lsst.daf.butler.core.safeFileIo Module

Functions

safeMakeDir(directory)	Make a directory in a manner avoiding race conditions
setFileMode(filename)	Set a file mode according to the user’s umask
FileForWriteOnceCompareSame(name)	Context manager to get a file that can be written only once and all other writes will succeed only if they match the initial write.
SafeFile(name)	Context manager to create a file in a manner avoiding race conditions
SafeFilename(name)	Context manager for creating a file in a manner avoiding race conditions.
SafeLockedFileForRead(name)	Context manager for reading a file that may be locked with an exclusive lock via SafeLockedFileForWrite.

Classes

DoNotWrite
FileForWriteOnceCompareSameFailure
SafeLockedFileForWrite(name)	File-like object that is used to create a file if needed, lock it with an exclusive lock, and contain file descriptors to readable and writable versions of the file.

Class Inheritance Diagram

lsst.daf.butler.core.utils Module

Functions

allSlots(self)	Return combined __slots__ for all classes in objects mro.
getClassOf(typeOrName, str])	Given the type name or a type, return the python type.
getFullTypeName(cls)	Return full type name of the supplied entity.
getInstanceOf(typeOrName, str], *args, **kwargs)	Given the type name or a type, instantiate an object of that type.
immutable(cls)	A class decorator that simulates a simple form of immutability for the decorated class.
iterable(a)	Make input iterable.
stripIfNotNone(s)	Strip leading and trailing whitespace if the given object is not None.
transactional(func)	Decorator that wraps a method and makes it transactional.

Classes

Singleton

Metaclass to convert a class to a Singleton.

Class Inheritance Diagram

lsst.daf.butler.core.repoRelocation Module

Functions

replaceRoot(configRoot, butlerRoot)

Update a configuration root with the butler root location.

Variables

BUTLER_ROOT_TAG

The special string to be used in configuration files to indicate that the butler root location should be used.

Test utilities

lsst.daf.butler.tests Package

Functions

addDatasetType(butler, name, dimensions, …)	Add a new dataset type to a repository.
expandUniqueId(butler, partialId)	Return a complete data ID matching some criterion.
makeTestCollection(repo)	Create a read/write Butler to a fresh collection.
makeTestRepo(root, dataIds, *[, config])	Create an empty repository with dummy data IDs.
registerMetricsExample(butler)	Modify a repository to support reading and writing MetricsExample objects.

Classes

BadNoWriteFormatter(fileDescriptor, dataId)	A formatter that always fails without writing anything.
BadWriteFormatter(fileDescriptor, dataId)	A formatter that never works but does leave a file behind.
DatasetTestHelper	Helper methods for Datasets
DatastoreTestHelper	Helper methods for Datastore tests
DummyRegistry()	Dummy Registry, for Datastore test purposes.
FitsCatalogDatasetsHelper
ListAssembler(storageClass)	Parameter handler for list parameters
MetricsAssembler(storageClass)	Parameter handler for parameters using Metrics
MetricsExample([summary, output, data])	Smorgasboard of information that might be the result of some processing.
MultiDetectorFormatter(fileDescriptor, dataId)