Blob¶

class lsst.verify.Blob(name, **datums)¶

Bases: lsst.verify.jsonmixin.JsonSerializationMixin

Blob is a flexible container of data, as lsst.verify.Datum s, that are serializable to JSON.

Parameters

namestr: Name of this type of blob. Blobs from one pipeline Job execution to another that share the same name generally share the same schema of lsst.verify.Datums.
datumsdict of lsst.verify.Datum-types, optional: Keys are names of datums. Values are Datum-types. Each Datum can be later retrived from the Blob instance by key.

Attributes Summary

`identifier`	Unique UUID4-based identifier for this blob (`str`).
`json`	Job data as a JSON-serializable `dict`.
`name`	Name of this blob (`str`).

Methods Summary

`deserialize`([identifier, name, data])	Deserialize fields from a blob JSON object into a `Blob` instance.
`items`()	Get pairs of keys and values in the Blob.
`jsonify_dict`(d)	Recursively build JSON-renderable objects on all values in a dict.
`keys`()	Get keys of blob items.
`write_json`(filepath)	Write JSON to a file.

Attributes Documentation

identifier¶: Unique UUID4-based identifier for this blob (str).

json¶: Job data as a JSON-serializable dict.

name¶: Name of this blob (str).

Methods Documentation

classmethod deserialize(identifier=None, name=None, data=None)¶

Deserialize fields from a blob JSON object into a Blob instance.

Parameters

identifierstr: Blob identifier.
namestr: Name of the blob type.
datadict: Dictionary of named name: datum object key-value pairs.

Returns

blobBlob: The Blob instance deserialied from a blob JSON object.

Examples

This class method is designed to roundtrip JSON objects created a Blob instance. For example:

>>> import astropy.units as u
>>> blob = Blob('demo')
>>> blob['a_mag'] = Datum(28 * u.mag, label='i')
>>> json_data = blob.json
>>> new_blob = Blob.deserialize(**json_data)

items()¶

Get pairs of keys and values in the Blob.

Yields

keyvaltuple

Tuple of:

key (str)
datum (lsst.verify.Datum)

static jsonify_dict(d)¶

Recursively build JSON-renderable objects on all values in a dict.

Parameters

ddict: Dictionary to convert into a JSON-serializable object. Values are recursively JSON-ified.

Returns

json_dictdict: Dictionary that can be serialized to JSON.

Examples

Subclasses can use this method to prepare output in their json-method implementation. For example:

def json(self):
    return JsonSerializationMixin.jsonify_dict({
        'value': self.value,
    })

keys()¶

Get keys of blob items.

Returns

keyssequence of str: Sequence of keys to items in the Blob.

write_json(filepath)¶

Write JSON to a file.

Parameters

filepathstr: Destination file name for JSON output.

Navigation

Blob¶