drb-impl-odata 1.0b2

DRB OData CSC implementation

OData CSC implementation

This drb-impl-odata module implements the OData protocol access following the Copernicus Space Component schema (CSC) with DRB data model. It is able to navigate among Product entities of a OData CSC service.

Nodes

ODataServiceNode

Represents the OData CSC service. This node has no attribute and has as children Product entities of the service defined by ProductNode. A specific ProductNode can be retrieved during the bracket and slash navigation by his Name(str) or by his Id(UUID).

CSC OData services required can be access using the second (optional) parameter auth of ODataServiceNode, this parameter must be an requests.auth.AuthBase object, see requests documentation for more details.

ODataProductNode

Represents a Product entity of the OData CSC service. This node has as attribute properties of the associated entity and has for unique child a ProductAttributeNode

ODataProductAttributeNode

This node allowing to represent the navigation link between the Product entity and its attributes. It has no attribute and has as children Attribute entities associated to the Product entity, defined by AttributeNode

ODataAttributeNode

Represents an Attribute entity. This node has no child and has as attribute properties associated to the Attribute entity.

Predicate

ODataCustomQuery

This predicate allows to retrieve a specific subset of children of an ODataServiceNode.

Installation

pip install drb-impl-odata

Examples

from uuid import UUID
from requests.auth import HTTPBasicAuth
from drb_impl_odata import ODataServiceNode, ODataProductNode,
    ODataAttributeNode, ODataQueryPredicate

# generate ODataServiceNode without authentication
odata = ODataServiceNode('https://my.csc.odata.com')
# generate ODataServiceNode with authentication mechanism
odata = ODataServiceNode('https://my.csc.odata.com',
                         auth=HTTPBasicAuth('usr', 'pwd'))

# total number of children
product_count = len(odata)

# retrieve first ODataProductNode
node_idx = odata[0]

# retrieve last ODataProductNode
node_idx = odata[-1]

# retrieve 10 first products
products = odata.children[:10]

# retrieve Product by name
name = 'S2B_OPER_MSI_L0__GR_EPAE_..._D05_N02.06.tar'
node_name_list = odata[name]  # returns a list
node_name = odata[name, 1]  # returns first occurrence of the list

# retrieve Product by UUID
uuid = UUID('0723d9bf-02a2-3e99-b1b3-f6d81de84b62')
node_uuid = odata[uuid]

# get product attributes
prd_node = odata[uuid]
attr_node = prd_node['Attributes', 1]['Footprint', 1]
attr_type = attr_node.get_attribute('ValueType')
attr_value = attr_node.value

# filter and order products
filtered_children = odata / ODataQueryPredicate(filter="startswith(Name,'S1')",
                                                order="ContentLength desc")