lc_resource

LcResource

Bases: object

This is a record that links a semantic reference to a physical data source, and specifies the capabilities (and someday, access limitations) of the data source.

The LcResource serializes to a json file with the following format: { ref: [ { "dataSource": source, "dataSourceType": ds_type, .... }, ... ] } where ref is the semantic reference.

__init__(origin, source, ds_type, interfaces=None, privacy=0, priority=50, static=False, preload_archive=None, config=None, **kwargs)

Parameters:

Name	Type	Description	Default
origin		semantic reference to data origin	required
source		physical data source; 'None' allowed if 'downloadLink' argument provided	required
ds_type		data source type	required
interfaces		list which can include 'entity', 'foreground', or 'background'. Default 'foreground'	None
privacy		Ignored / No longer used.	0
priority		[50] priority level.. numeric (nominally 0-100), lowest priority resource is loaded first	50
static		[False] if True, load_all() after initializing	False
preload_archive		[None] use to assign an existing archive	None
config		ConfigureInterface specifications	None
kwargs		additional keyword arguments to constructor. Some interesting ones: download: a dict containing 'url' and optional 'md5sum' fields prefix: often used when accessing zipped archives token: a jwt used for authenticating to xdb 'options': popped with values used as kwargs (per ResourceSpec)	{}

from_dict(ref, d) classmethod

Returns a single LcResource loaded from a dict. only required field is 'dataSourceType'. other fields are passed to the constructor and either interpreted directly or added as supplemental args

If 'dataSource' is not present, one had better hope that url is present in the dict to download the source

Parameters:

Name	Type	Description	Default
ref			required
d			required

Returns:

Type	Description

from_file(file) classmethod

generates LcResources contained in the named file, sorted by increasing priority. The filename and the reference must be the same.

Parameters:

Name	Type	Description	Default
file			required

Returns:

Type	Description
	an ordered list of resources

matches(k)

Pretty cheesy. When we serialize a set of resources, we need to make sure not to include self twice. To make the comparison concrete, use a serialized resource as input.

We were using dataSource as a unique identifier for resource entries; but the introduction of download links breaks that because a downloadable resource has no source until it's been downloaded. The solution is to fallback to download.url ONLY IF the resource has no source specified.

Parameters:

Name	Type	Description	Default
k		a serialized LcResource	required

Returns:

Type	Description

write_to_file(path, assign_ref=None, apply_config=None)

Adds the resource to a file whose name is the resource's semantic reference. If the same datasource is already present in the file, replace it with the current resource. otherwise append.

Parameters:

Name	Type	Description	Default
path		directory to store the resource file.	required
assign_ref		assign this ref instead of the resource's current ref	None
apply_config		overwrites configuration with supplied dict	None

Returns:

Type	Description

ResourceInvalid

Bases: Exception

resource points to an invalid filename