Metadata¶

class lsst.verify.Metadata(measurement_set, data=None)¶

Container for verification framework job metadata.

Metadata are key-value terms. Both keys and values should be JSON-serializable.

Parameters:	measurement_set : `lsst.verify.MeasurementSet`, optional When provided, metadata with keys prefixed by metric names are deferred to `Metadata` instances attached to measurements (`lsst.verify.Measurement.notes`). data : `dict`, optional Dictionary to seed metadata.

Attributes Summary

json A dict that can be serialized as semantic SQUASH JSON.

Methods Summary

`items`()	Iterate over key-value metadata pairs.
`jsonify_dict`(d)	Recursively build JSON-renderable objects on all values in a dict.
`keys`()	Get a `list` of metadata keys.
`update`(data)	Update metadata with key-value pairs from a `dict`-like object.
`write_json`(filepath)	Write JSON to a file.

Attributes Documentation

json¶

A dict that can be serialized as semantic SQUASH JSON.

Keys in the dict are metadata keys (see Metadata.keys). Values are the associated metadata values as JSON-serializable objects.

Methods Documentation

items()¶

Iterate over key-value metadata pairs.

Yields:	item : `tuple` A metadata item is a tuple of: Key (`str`). Value (object).

static jsonify_dict(d)¶

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

Parameters:	d : `dict` Dictionary to convert into a JSON-serializable object. Values are recursively JSON-ified.
Returns:	json_dict : `dict` 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 a list of metadata keys.

Returns:	keys : `list` of `str` These keys keys can be used to access metadata values (like a `dict`).

update(data)¶

Update metadata with key-value pairs from a dict-like object.

Parameters:	data : `dict`-like The `data` object needs to provide an `items` method to iterate over its key-value pairs. If this `Metadata` instance already has a key, the value will be overwritten with the value from `data`.

write_json(filepath)¶

Write JSON to a file.

Parameters:	filepath : `str` Destination file name for JSON output.