GeoEco.Datasets.Collections.FileDatasetCollection

class GeoEco.Datasets.Collections.FileDatasetCollection(path, decompressedFileToReturn=None, parentCollection=None, queryableAttributes=None, queryableAttributeValues=None, lazyPropertyValues=None, cacheDirectory=None)

Bases: DatasetCollection

Base class representing a DatasetCollection that is a file containing one or more Datasets.

FileDatasetCollection is a base class that should not be instantiated directly; instead, users should instantiate one of the derived classes representing the type of file they’re interested in.

Parameters:

path (str) –
Path to the file to open.

If there is no parent collection, this is the full path to the file. It will be opened as stand-alone collection.

If there is a parent collection, this path is relative to it. For example, if the parent collection is a DirectoryTree, this path is relative to a leaf directory of the DirectoryTree. Often, the leaf directory will be the one containing the file, in which case the path provided here will simply be the name of the file.

If the path points to compressed file, it will be decompressed automatically. If a cache directory is provided, it will be checked first for an existing decompressed file. If none is found the file will be decompressed there.

If the compressed file is an archive (e.g. .zip or .tar), you must also specify a decompressed file to return.

Minimum length꞉ 1.
decompressedFileToReturn (str, optional) –
glob() expression that identifies the extracted file to open when the path points to an archive (e.g. a .zip or .tar file).

This expression must select exactly one of the extracted files. Be sure to leave it as None when the path does not point to an archive. Minimum length꞉ 1.
parentCollection (DatasetCollection, optional) – Parent DatasetCollection that this object is part of (if any).
queryableAttributes (tuple of QueryableAttribute, optional) – Queryable attributes defined for this object.
queryableAttributeValues (dict mapping str to object, optional) – Values of the queryable attributes, expressed as a dictionary mapping the case-insensitive names of queryable attributes to their values.
lazyPropertyValues (dict mapping str to object, optional) – Lazy properties to set when this object is constructed, expressed as a dictionary mapping the names of lazy properties to their values.
cacheDirectory (str, optional) –
Directory to cache a copy of the downloaded or decompressed file.

If provided, this directory will be checked for the file prior to download or decompression. If the file is found, the download and decompression will be skipped. Thus, when performing repetitive processing with remote or compressed datasets, you can speed up processing considerably by providing a cache directory.

Minimum length꞉ 1.

Returns:

FileDatasetCollection instance.

Return type:

FileDatasetCollection

Properties

property CacheDirectory

(str or None) Directory for caching local copies of remote datasets. Minimum length꞉ 1. If a cache directory is not provided, then after a remote dataset is downloaded it will be kept either only in memory or in a temporary directory on disk, depending on the type of data it is. The temporary directory will be automatically deleted when Close() is called.

If a cache directory is provided, remote datasets will be stored in it when they are downloaded. Before a download is attempted, the cache directory will be checked first for the relevant dataset, and if it is found, the download will be skipped, speeding up execution.

The datasets are organized in the cache directory in an undocumented format that is specific to the collection. Once a dataset is stored in the cache directory, it is never changed or deleted. If the original remote datasets are changed, these changes will not be detected and the cache will not be updated. If the disk fills up, cached datasets will not be automatically deleted to mitigate the problem.

If you determine that the cached datasets are obsolete or the disk is too full, delete the entire cache directory. You may also be able to delete a portion of it, if you can reverse engineer how datasets are stored within it, but the organizational structure is not documented.

property DecompressedFileToReturn: (str or None) glob() expression that identifies the extracted file to open when the path points to an archive (e.g. a .zip or .tar file). Read only. Minimum length꞉ 1. This expression must select exactly one of the extracted files. Be sure to leave it as None when the path does not point to an archive.

property DisplayName: (str) Informal name of this object, suitable to be displayed to the user. Read only. Minimum length꞉ 1.

property ParentCollection: (DatasetCollection or None) Parent DatasetCollection that this object is part of (if any). Read only.

property Path

(str) Path to the file to open. Read only. Minimum length꞉ 1. If there is no parent collection, this is the full path to the file. It will be opened as stand-alone collection.

If there is a parent collection, this path is relative to it. For example, if the parent collection is a DirectoryTree, this path is relative to a leaf directory of the DirectoryTree. Often, the leaf directory will be the one containing the file, in which case the path provided here will simply be the name of the file.

If the path points to compressed file, it will be decompressed automatically. If a cache directory is provided, it will be checked first for an existing decompressed file. If none is found the file will be decompressed there.

If the compressed file is an archive (e.g. .zip or .tar), you must also specify a decompressed file to return.

Methods

`Close`	Closes any open files or connections associated with this object and releases any other resources allocated to access it.
`DeleteLazyPropertyValue`	Deletes the lazy property with the specified name.
`GetAllQueryableAttributes`	Returns a list of all queryable attributes.
`GetLazyPropertyValue`	Returns the value of the lazy property with the specified name.
`GetNewestDataset`	Queries the collection and returns the newest `Dataset` that matches the search expression.
`GetOldestDataset`	Queries the collection and returns the oldest `Dataset` that matches the search expression.
`GetQueryableAttribute`	Returns the queryable attribute with the specified name.
`GetQueryableAttributeValue`	Returns the value of the queryable attribute with the specified name.
`GetQueryableAttributesWithDataType`	Returns a list queryable attributes having the specified data type.
`HasLazyPropertyValue`	Returns True if the specified lazy property has a value.
`ImportDatasets`	Copies each `Dataset` in a `list` into this `DatasetCollection`.
`QueryDatasets`	Queries the collection and returns a `list` of `Dataset`s that match a search expression.
`SetLazyPropertyValue`	Sets the lazy property with the specified name to the specified value.
`TestCapability`	Tests whether a capability is supported by this class or an instance of it.