StubTranslator¶

class astro_metadata_translator.StubTranslator(header: Mapping[str, Any], filename: str | None = None)¶

Bases: MetadataTranslator

Translator where all the translations are stubbed out and issue warnings.

This translator can be used as a base class whilst developing a new translator. It allows testing to proceed without being required to fully define all translation methods. Once complete the class should be removed from the inheritance tree.

Attributes Summary

`all_properties`	All the valid properties for this translator including extensions.
`default_resource_package`	Module name to use to locate the correction resources.
`default_resource_root`	Default package resource path root to use to locate header correction files within the `default_resource_package` package.
`default_search_path`	Default search path to use to locate header correction files.
`extensions`	Extension properties (`str`: `PropertyDefinition`)
`name`	The declared name of the translator.
`supported_instrument`	Name of instrument understood by this translation class.
`translators`	All registered metadata translation classes.

Methods Summary

`are_keys_ok`(keywords)	Are the supplied keys all present and defined?.
`can_translate`(header[, filename])	Indicate whether this translation class can translate the supplied header.
`can_translate_with_options`(header, options)	Determine if a header can be translated with different criteria.
`cards_used`()	Cards used during metadata extraction.
`defined_in_this_class`(name)	Report if the specified class attribute is defined specifically in this class.
`determine_translatable_headers`(filename[, ...])	Given a file return all the headers usable for metadata translation.
`determine_translator`(header[, filename])	Determine a translation class by examining the header.
`fix_header`(header, instrument, obsid[, filename])	Apply global fixes to a supplied header.
`is_key_ok`(keyword)	Return `True` if the value associated with the named keyword is present in this header and defined.
`is_keyword_defined`(header, keyword)	Return `True` if the value associated with the named keyword is present in the supplied header and defined.
`observing_date_to_observing_day`(...)	Return the YYYYMMDD integer corresponding to the observing day.
`observing_date_to_offset`(observing_date)	Calculate the observing day offset to apply for a given observation.
`quantity_from_card`(keywords, unit[, ...])	Calculate a Astropy Quantity from a header card and a unit.
`resource_root`()	Return package resource to use to locate correction resources within an installed package.
`search_paths`()	Search paths to use when searching for header fix up correction files.
`to_altaz_begin`()	Unimplemented forwarding translator for altaz_begin.
`to_boresight_airmass`()	Unimplemented forwarding translator for boresight_airmass.
`to_boresight_rotation_angle`()	Unimplemented forwarding translator for boresight_rotation_angle.
`to_boresight_rotation_coord`()	Unimplemented forwarding translator for boresight_rotation_coord.
`to_can_see_sky`()	Unimplemented forwarding translator for can_see_sky.
`to_dark_time`()	Unimplemented forwarding translator for dark_time.
`to_datetime_begin`()	Unimplemented forwarding translator for datetime_begin.
`to_datetime_end`()	Unimplemented forwarding translator for datetime_end.
`to_detector_exposure_id`()	Unimplemented forwarding translator for detector_exposure_id.
`to_detector_group`()	Unimplemented forwarding translator for detector_group.
`to_detector_name`()	Unimplemented forwarding translator for detector_name.
`to_detector_num`()	Unimplemented forwarding translator for detector_num.
`to_detector_serial`()	Unimplemented forwarding translator for detector_serial.
`to_detector_unique_name`()	Unimplemented forwarding translator for detector_unique_name.
`to_exposure_group`()	Unimplemented forwarding translator for exposure_group.
`to_exposure_id`()	Unimplemented forwarding translator for exposure_id.
`to_exposure_time`()	Unimplemented forwarding translator for exposure_time.
`to_focus_z`()	Unimplemented forwarding translator for focus_z.
`to_group_counter_end`()	Unimplemented forwarding translator for group_counter_end.
`to_group_counter_start`()	Unimplemented forwarding translator for group_counter_start.
`to_has_simulated_content`()	Unimplemented forwarding translator for has_simulated_content.
`to_instrument`()	Unimplemented forwarding translator for instrument.
`to_location`()	Unimplemented forwarding translator for location.
`to_object`()	Unimplemented forwarding translator for object.
`to_observation_counter`()	Unimplemented forwarding translator for observation_counter.
`to_observation_id`()	Unimplemented forwarding translator for observation_id.
`to_observation_reason`()	Unimplemented forwarding translator for observation_reason.
`to_observation_type`()	Unimplemented forwarding translator for observation_type.
`to_observing_day`()	Unimplemented forwarding translator for observing_day.
`to_observing_day_offset`()	Unimplemented forwarding translator for observing_day_offset.
`to_physical_filter`()	Unimplemented forwarding translator for physical_filter.
`to_pressure`()	Unimplemented forwarding translator for pressure.
`to_relative_humidity`()	Unimplemented forwarding translator for relative_humidity.
`to_science_program`()	Unimplemented forwarding translator for science_program.
`to_telescope`()	Unimplemented forwarding translator for telescope.
`to_temperature`()	Unimplemented forwarding translator for temperature.
`to_tracking_radec`()	Unimplemented forwarding translator for tracking_radec.
`to_visit_id`()	Unimplemented forwarding translator for visit_id.
`translator_version`()	Return the version string for this translator class.
`validate_value`(value, default[, minimum, ...])	Validate the supplied value, returning a new value if out of range.

Attributes Documentation

all_properties: dict[str, astro_metadata_translator.properties.PropertyDefinition] = {'altaz_begin': PropertyDefinition(doc='Telescope boresight azimuth and elevation at start of observation.', str_type='astropy.coordinates.AltAz', py_type=<class 'astropy.coordinates.builtin_frames.altaz.AltAz'>, to_simple=<function altaz_to_simple>, from_simple=<function simple_to_altaz>), 'boresight_airmass': PropertyDefinition(doc='Airmass of the boresight of the telescope.', str_type='float', py_type=<class 'float'>, to_simple=None, from_simple=None), 'boresight_rotation_angle': PropertyDefinition(doc='Angle of the instrument in boresight_rotation_coord frame.', str_type='astropy.coordinates.Angle', py_type=<class 'astropy.coordinates.angles.core.Angle'>, to_simple=<function angle_to_simple>, from_simple=<function simple_to_angle>), 'boresight_rotation_coord': PropertyDefinition(doc='Coordinate frame of the instrument rotation angle (options: sky, unknown).', str_type='str', py_type=<class 'str'>, to_simple=None, from_simple=None), 'can_see_sky': PropertyDefinition(doc='True if the observation is looking at sky, False if it is definitely not looking at the sky. None indicates that it is not known whether sky could be seen.', str_type='bool', py_type=<class 'bool'>, to_simple=None, from_simple=None), 'dark_time': PropertyDefinition(doc='Duration of the exposure with shutter closed (seconds).', str_type='astropy.units.Quantity', py_type=<class 'astropy.units.quantity.Quantity'>, to_simple=<function exptime_to_simple>, from_simple=<function simple_to_exptime>), 'datetime_begin': PropertyDefinition(doc='Time of the start of the observation.', str_type='astropy.time.Time', py_type=<class 'astropy.time.core.Time'>, to_simple=<function datetime_to_simple>, from_simple=<function simple_to_datetime>), 'datetime_end': PropertyDefinition(doc='Time of the end of the observation.', str_type='astropy.time.Time', py_type=<class 'astropy.time.core.Time'>, to_simple=<function datetime_to_simple>, from_simple=<function simple_to_datetime>), 'detector_exposure_id': PropertyDefinition(doc='Unique integer identifier for this detector in this exposure.', str_type='int', py_type=<class 'int'>, to_simple=None, from_simple=None), 'detector_group': PropertyDefinition(doc='Collection name of which this detector is a part. Can be None if there are no detector groupings.', str_type='str', py_type=<class 'str'>, to_simple=None, from_simple=None), 'detector_name': PropertyDefinition(doc='Name of the detector within the instrument (might not be unique if there are detector groups).', str_type='str', py_type=<class 'str'>, to_simple=None, from_simple=None), 'detector_num': PropertyDefinition(doc='Unique (for instrument) integer identifier for the sensor.', str_type='int', py_type=<class 'int'>, to_simple=None, from_simple=None), 'detector_serial': PropertyDefinition(doc='Serial number/string associated with this detector.', str_type='str', py_type=<class 'str'>, to_simple=None, from_simple=None), 'detector_unique_name': PropertyDefinition(doc='Unique name of the detector within the focal plane, generally combining detector_group with detector_name.', str_type='str', py_type=<class 'str'>, to_simple=None, from_simple=None), 'exposure_group': PropertyDefinition(doc="Label to use to associate this exposure with others (can be related to 'exposure_id').", str_type='str', py_type=<class 'str'>, to_simple=None, from_simple=None), 'exposure_id': PropertyDefinition(doc='Unique (with instrument) integer identifier for this observation.', str_type='int', py_type=<class 'int'>, to_simple=None, from_simple=None), 'exposure_time': PropertyDefinition(doc='Duration of the exposure with shutter open (seconds).', str_type='astropy.units.Quantity', py_type=<class 'astropy.units.quantity.Quantity'>, to_simple=<function exptime_to_simple>, from_simple=<function simple_to_exptime>), 'focus_z': PropertyDefinition(doc='Defocal distance.', str_type='astropy.units.Quantity', py_type=<class 'astropy.units.quantity.Quantity'>, to_simple=<function focusz_to_simple>, from_simple=<function simple_to_focusz>), 'group_counter_end': PropertyDefinition(doc='Observation counter for the end of the exposure group. Depending on the instrument the relevant group may be visit_id or exposure_group.', str_type='int', py_type=<class 'int'>, to_simple=None, from_simple=None), 'group_counter_start': PropertyDefinition(doc='Observation counter for the start of the exposure group.Depending on the instrument the relevant group may be visit_id or exposure_group.', str_type='int', py_type=<class 'int'>, to_simple=None, from_simple=None), 'has_simulated_content': PropertyDefinition(doc='Boolean indicating whether any part of this observation was simulated.', str_type='bool', py_type=<class 'bool'>, to_simple=None, from_simple=None), 'instrument': PropertyDefinition(doc='The instrument used to observe the exposure.', str_type='str', py_type=<class 'str'>, to_simple=None, from_simple=None), 'location': PropertyDefinition(doc='Location of the observatory.', str_type='astropy.coordinates.EarthLocation', py_type=<class 'astropy.coordinates.earth.EarthLocation'>, to_simple=<function earthlocation_to_simple>, from_simple=<function simple_to_earthlocation>), 'object': PropertyDefinition(doc='Object of interest or field name.', str_type='str', py_type=<class 'str'>, to_simple=None, from_simple=None), 'observation_counter': PropertyDefinition(doc='Counter of this observation. Can be counter within observing_day or a global counter. Likely to be observatory specific.', str_type='int', py_type=<class 'int'>, to_simple=None, from_simple=None), 'observation_id': PropertyDefinition(doc="Label uniquely identifying this observation (can be related to 'exposure_id').", str_type='str', py_type=<class 'str'>, to_simple=None, from_simple=None), 'observation_reason': PropertyDefinition(doc="Reason this observation was taken, or its purpose ('science' and 'calibration' are common values)", str_type='str', py_type=<class 'str'>, to_simple=None, from_simple=None), 'observation_type': PropertyDefinition(doc='Type of observation (currently: science, dark, flat, bias, focus).', str_type='str', py_type=<class 'str'>, to_simple=None, from_simple=None), 'observing_day': PropertyDefinition(doc='Integer in YYYYMMDD format corresponding to the day of observation.', str_type='int', py_type=<class 'int'>, to_simple=None, from_simple=None), 'observing_day_offset': PropertyDefinition(doc='Offset to subtract from an observation date when calculating the observing day. Conversely, the offset to add to an observing day when calculating the time span of a day.', str_type='astropy.time.TimeDelta', py_type=<class 'astropy.time.core.TimeDelta'>, to_simple=<function timedelta_to_simple>, from_simple=<function simple_to_timedelta>), 'physical_filter': PropertyDefinition(doc='The bandpass filter used for this observation.', str_type='str', py_type=<class 'str'>, to_simple=None, from_simple=None), 'pressure': PropertyDefinition(doc='Atmospheric pressure outside the dome.', str_type='astropy.units.Quantity', py_type=<class 'astropy.units.quantity.Quantity'>, to_simple=<function pressure_to_simple>, from_simple=<function simple_to_pressure>), 'relative_humidity': PropertyDefinition(doc='Relative humidity outside the dome.', str_type='float', py_type=<class 'float'>, to_simple=None, from_simple=None), 'science_program': PropertyDefinition(doc='Observing program (survey or proposal) identifier.', str_type='str', py_type=<class 'str'>, to_simple=None, from_simple=None), 'telescope': PropertyDefinition(doc='Full name of the telescope.', str_type='str', py_type=<class 'str'>, to_simple=None, from_simple=None), 'temperature': PropertyDefinition(doc='Temperature outside the dome.', str_type='astropy.units.Quantity', py_type=<class 'astropy.units.quantity.Quantity'>, to_simple=<function temperature_to_simple>, from_simple=<function simple_to_temperature>), 'tracking_radec': PropertyDefinition(doc='Requested RA/Dec to track.', str_type='astropy.coordinates.SkyCoord', py_type=<class 'astropy.coordinates.sky_coordinate.SkyCoord'>, to_simple=<function skycoord_to_simple>, from_simple=<function simple_to_skycoord>), 'visit_id': PropertyDefinition(doc='ID of the Visit this Exposure is associated with.\n\nScience observations should essentially always be\nassociated with a visit, but calibration observations\nmay not be.', str_type='int', py_type=<class 'int'>, to_simple=None, from_simple=None)}¶: All the valid properties for this translator including extensions.

default_resource_package = 'astro_metadata_translator'¶: Module name to use to locate the correction resources.

default_resource_root: str | None = None¶: Default package resource path root to use to locate header correction files within the default_resource_package package.

default_search_path: Sequence[str] | None = None¶: Default search path to use to locate header correction files.

extensions: dict[str, astro_metadata_translator.properties.PropertyDefinition] = {}¶

Extension properties (str: PropertyDefinition)

Some instruments have important properties beyond the standard set; this is the place to declare that they exist, and they will be treated in the same way as the standard set, except that their names will everywhere be prefixed with ext_.

Each property is indexed by name (str), with a corresponding PropertyDefinition.

name: str | None = None¶: The declared name of the translator.

supported_instrument: str | None = None¶: Name of instrument understood by this translation class.

translators: dict[str, type[astro_metadata_translator.translator.MetadataTranslator]] = {'DECam': <class 'astro_metadata_translator.translators.decam.DecamTranslator'>, 'HSC': <class 'astro_metadata_translator.translators.hsc.HscTranslator'>, 'MegaPrime': <class 'astro_metadata_translator.translators.megaprime.MegaPrimeTranslator'>, 'SDSS': <class 'astro_metadata_translator.translators.sdss.SdssTranslator'>, 'SuprimeCam': <class 'astro_metadata_translator.translators.suprimecam.SuprimeCamTranslator'>}¶: All registered metadata translation classes.

Methods Documentation

are_keys_ok(keywords: Iterable[str]) → bool¶

Are the supplied keys all present and defined?.

Parameters:

keywordsiterable of str: Keywords to test.

Returns:

all_okbool: True if all supplied keys are present and defined.

abstract classmethod can_translate(header: Mapping[str, Any], filename: str | None = None) → bool¶

Indicate whether this translation class can translate the supplied header.

Parameters:

headerdict-like: Header to convert to standardized form.
filenamestr, optional: Name of file being translated.

Returns:

canbool: True if the header is recognized by this class. False otherwise.

classmethod can_translate_with_options(header: Mapping[str, Any], options: dict[str, Any], filename: str | None = None) → bool¶

Determine if a header can be translated with different criteria.

Parameters:

headerdict-like: Header to convert to standardized form.
optionsdict: Headers to try to determine whether this header can be translated by this class. If a card is found it will be compared with the expected value and will return that comparison. Each card will be tried in turn until one is found.
filenamestr, optional: Name of file being translated.

Returns:

canbool: True if the header is recognized by this class. False otherwise.

Notes

Intended to be used from within can_translate implementations for specific translators. Is not intended to be called directly from determine_translator.

cards_used() → frozenset[str]¶

Cards used during metadata extraction.

Returns:

usedfrozenset of str: Cards used when extracting metadata.

classmethod defined_in_this_class(name: str) → bool | None¶

Report if the specified class attribute is defined specifically in this class.

Parameters:

namestr: Name of the attribute to test.

Returns:

in_classbool: True if there is a attribute of that name defined in this specific subclass. False if the method is not defined in this specific subclass but is defined in a parent class. Returns None if the attribute is not defined anywhere in the class hierarchy (which can happen if translators have typos in their mapping tables).

Notes

Retrieves the attribute associated with the given name. Then looks in all the parent classes to determine whether that attribute comes from a parent class or from the current class. Attributes are compared using id().

classmethod determine_translatable_headers(filename: str, primary: MutableMapping[str, Any] | None = None) → Iterator[MutableMapping[str, Any]]¶

Given a file return all the headers usable for metadata translation.

This method can optionally be given a header from the file. This header will generally be the primary header or a merge of the first two headers.

In the base class implementation it is assumed that this supplied header is the only useful header for metadata translation and it will be returned unchanged if given. This can avoid unnecessarily re-opening the file and re-reading the header when the content is already known.

If no header is supplied, a header will be read from the supplied file using read_basic_metadata_from_file, allowing it to merge the primary and secondary header of a multi-extension FITS file. Subclasses can read the header from the data file using whatever technique is best for that instrument.

Subclasses can return multiple headers and ignore the externally supplied header. They can also merge it with another header and return a new derived header if that is required by the particular data file. There is no requirement for the supplied header to be used.

Parameters:

filenamestr: Path to a file in a format understood by this translator.
primarydict-like, optional: The primary header obtained by the caller. This is sometimes already known, for example if a system is trying to bootstrap without already knowing what data is in the file. For many instruments where the primary header is the only relevant header, the primary header will be returned with no further action.

Yields:

headersiterator of dict-like: A header usable for metadata translation. For this base implementation it will be either the supplied primary header or a header read from the file. This implementation will only ever yield a single header.

Notes

Each translator class can have code specifically tailored to its own file format. It is important not to call this method with an incorrect translator class. The normal paradigm is for the caller to have read the first header and then called determine_translator() on the result to work out which translator class to then call to obtain the real headers to be used for translation.

classmethod determine_translator(header: Mapping[str, Any], filename: str | None = None) → type[astro_metadata_translator.translator.MetadataTranslator]¶

Determine a translation class by examining the header.

Parameters:

headerdict-like: Representation of a header.
filenamestr, optional: Name of file being translated.

Returns:

translatorMetadataTranslator: Translation class that knows how to extract metadata from the supplied header.

Raises:

ValueError: None of the registered translation classes understood the supplied header.

classmethod fix_header(header: MutableMapping[str, Any], instrument: str, obsid: str, filename: str | None = None) → bool¶

Apply global fixes to a supplied header.

Parameters:

headerdict: The header to correct. Correction is in place.
instrumentstr: The name of the instrument.
obsidstr: Unique observation identifier associated with this header. Will always be provided.
filenamestr, optional: Filename associated with this header. May not be set since headers can be fixed independently of any filename being known.

Returns:

modifiedbool: True if a correction was applied.

Notes

This method is intended to support major discrepancies in headers such as:

Periods of time where headers are known to be incorrect in some way that can be fixed either by deriving the correct value from the existing value or understanding the that correction is static for the given time. This requires that the date header is known.
The presence of a certain value is always wrong and should be corrected with a new static value regardless of date.

It is assumed that one off problems with headers have been applied before this method is called using the per-obsid correction system.

Usually called from astro_metadata_translator.fix_header.

For log messages, do not assume that the filename will be present. Always write log messages to fall back on using the obsid if filename is None.

is_key_ok(keyword: str | None) → bool¶

Return True if the value associated with the named keyword is present in this header and defined.

Parameters:

keywordstr: Keyword to check against header.

Returns:

is_okbool: True if the header is present and not-None. False otherwise.

static is_keyword_defined(header: Mapping[str, Any], keyword: str | None) → bool¶

Return True if the value associated with the named keyword is present in the supplied header and defined.

Parameters:

headerdict-lik: Header to use as reference.
keywordstr: Keyword to check against header.

Returns:

is_definedbool: True if the header is present and not-None. False otherwise.

classmethod observing_date_to_observing_day(observing_date: Time, offset: TimeDelta | int | None) → int¶

Return the YYYYMMDD integer corresponding to the observing day.

The offset is subtracted from the time of observation before calculating the year, month and day.

Parameters:

observing_dateastropy.time.Time: The observation date.
offsetastropy.time.TimeDelta | numbers.Real | None: The offset to subtract from the observing date when calculating the observing day. If a plain number is given it is taken to be in units of seconds. If None no offset is applied.

Returns:

dayint: The observing day as an integer of form YYYYMMDD.

Notes

For example, if the offset is +12 hours both 2023-07-06T13:00 and 2023-07-07T11:00 will return an observing day of 20230706 because the observing day goes from 2023-07-06T12:00 to 2023-07-07T12:00.

classmethod observing_date_to_offset(observing_date: Time) → TimeDelta | None¶

Calculate the observing day offset to apply for a given observation.

In some cases the definition of the observing day offset has changed during the lifetime of the instrument. For example lab data might have a different offset to that when the instrument is on the telescope.

Parameters:

observing_dateastropy.time.Time: The observation date.

Returns:

offsetastropy.time.TimeDelta or None: The offset to apply when calculating the observing day for a specific time of observation. None implies the offset is not known for that date.

Calculate a Astropy Quantity from a header card and a unit.

Parameters:

keywordsstr or list of str: Keyword to use from header. If a list each keyword will be tried in turn until one matches.
unitastropy.units.UnitBase: Unit of the item in the header.
defaultfloat, optional: Default value to use if the header value is invalid. Assumed to be in the same units as the value expected in the header. If None, no default value is used.
minimumfloat, optional: Minimum possible valid value, optional. If the calculated value is below this value, the default value will be used.
maximumfloat, optional: Maximum possible valid value, optional. If the calculated value is above this value, the default value will be used.
checkerCallable, optional: Callback function to be used by the translator method in case the keyword is not present. Function will be executed as if it is a method of the translator class. Running without raising an exception will allow the default to be used. Should usually raise KeyError.

Returns:

qastropy.units.Quantity: Quantity representing the header value.

Raises:

KeyError: The supplied header key is not present.

resource_root() → tuple[str | None, str | None]¶

Return package resource to use to locate correction resources within an installed package.

Returns:

resource_packagestr: Package resource name. None if no package resource are to be used.
resource_rootstr: The name of the resource root. None if no package resources are to be used.

search_paths() → list[str]¶

Search paths to use when searching for header fix up correction files.

Returns:

pathslist: Directory paths to search. Can be an empty list if no special directories are defined.

Notes

Uses the classes default_search_path property if defined.

to_altaz_begin() → Any¶

Unimplemented forwarding translator for altaz_begin.

True if the observation is looking at sky, False if it is definitely not looking at the sky. None indicates that it is not known whether sky could be seen.