Service¶

`Service`	The default Descartes Labs HTTP Service used to communicate with its servers.
`JsonApiService`	A JsonApi oriented default Descateslabs Labs HTTP Service.
`ThirdPartyService`	The default Descartes Labs HTTP Service used for 3rd party servers.
`Session`	The HTTP Session that performs the actual HTTP request.
`JsonApiSession`	The HTTP Session that performs the actual JSONAPI HTTP request.

class Service(url, token=None, auth=None, retries=None, session_class=None)[source]¶

The default Descartes Labs HTTP Service used to communicate with its servers.

This service has a default timeout and retry policy that retries HTTP requests depending on the timeout and HTTP status code that was returned. This is based on the requests timeouts and the urllib3 retry object.

The default timeouts are set to 9.5 seconds for establishing a connection (slightly larger than a multiple of 3, which is the TCP default packet retransmission window), and 30 seconds for reading a response.

The default retry logic retries up to 3 times total, a maximum of 2 for establishing a connection, 2 for reading a response, and 2 for unexpected HTTP status codes. The backoff_factor is a random number between 1 and 3, but will never be more than 2 minutes. The unexpected HTTP status codes that will be retried are 500, 502, 503, and 504 for any of the HTTP requests. Note that 429s are retried automatically according to their retry-after headers without us specifying anything here (see the source for urllib3.util.Retry as the API documentation doesn’t make this clear).

Parameters

url (str) – The URL prefix to use for communication with the Descartes Labs server.
token (str, optional) – Deprecated.
auth (Auth, optional) – A Descartes Labs Auth instance. If not provided, a default one will be instantiated.
retries (int or urllib3.util.retry.Retry) – If a number, it’s the number of retries that will be attempled. If a urllib3.util.retry.Retry instance, it will determine the retry behavior. If not provided, the default retry policy as described above will be used.
session_class (class) – The session class to use when instantiating the session. This must be a derived class from Session. If not provided, the default session class is used. You can register a default session class with Service.set_default_session_class().

Raises

TypeError – If you try to use a session class that is not derived from Session.

Methods:

`get_default_session_class`()	Get the default session class for `Service`.
`set_default_session_class`(session_class)	Set the default session class for `Service`.

Attributes:

`session`	The session instance used by this service.
`token`	The bearer token used in the requests.

classmethod get_default_session_class()[source]¶

Get the default session class for Service.

Returns: The default session class, which is Session itself or a derived class from Session.
Return type: Session

classmethod set_default_session_class(session_class)[source]¶

Set the default session class for Service.

The default session is used for any Service that is instantiated without specifying the session class.

Parameters: session_class (class) – The session class to use when instantiating the session. This must be the class Session itself or a derived class from Session.

property session¶

The session instance used by this service.

Type: Session

property token¶

The bearer token used in the requests.

Type: str

class JsonApiService(url, session_class=None, rewrite_errors=False, **kwargs)[source]¶

Bases: descarteslabs.client.services.service.service.Service

A JsonApi oriented default Descateslabs Labs HTTP Service.

For details see the Service. This service adheres to the JsonApi standard and interprets responses as needed.

This service uses the JsonApiSession which provides some optional functionality.

Parameters

url (str) – The URL prefix to use for communication with the Descartes Labs servers.
session_class (class) – The session class to use when instantiating the session. This must be a derived class from JsonApiSession. If not provided, the default session class is used. You can register a default session class with JsonApiService.set_default_session_class().
rewrite_errors (bool) – When set to True, errors are rewritten to be more readable. Each JsonApi error becomes a single line of error information without tags.
auth (Auth, optional) – A Descartes Labs Auth instance. If not provided, a default one will be instantiated.
retries (int or urllib3.util.retry.Retry If a number, it's the number of retries) – that will be attempled. If a urllib3.util.retry.Retry instance, it will determine the retry behavior. If not provided, the default retry policy as described above will be used.

Raises

TypeError – If you try to use a session class that is not derived from JsonApiSession.

Methods:

`get_default_session_class`()	Get the default session class for `JsonApiService`.
`jsonapi_collection`(type, attributes_list[, …])	Return a JsonApi document with a collection of resources.
`jsonapi_document`(type, attributes[, id])	Return a JsonApi document with a single resource.
`set_default_session_class`(session_class)	Set the default session class for `JsonApiService`.

Attributes:

`session`	The session instance used by this service.
`token`	The bearer token used in the requests.

classmethod get_default_session_class()[source]¶

Get the default session class for JsonApiService.

Returns: The default session class, which is JsonApiService itself or a derived class from JsonApiService.
Return type: JsonApiService

static jsonapi_collection(type, attributes_list, ids_list=None)[source]¶

Return a JsonApi document with a collection of resources.

The number of elements in the attributes_list must be identical to the number of elements in the ids_list.

A JsonApi collection has the following structure:

{
    "data": [
        {
            "type": "...",
            "id": "...",  // Optional
            "attributes": {
                "...": "...",
                ...
            }
        }, {
            ...
        }, {
        ...
    ]
}

Parameters

type (str) – The type of resource; this becomes the type key for each resource in the collection. The JsonApi collection contains resources of the same type.
attributes (list(dict)) – A list of attributes for each resource; this becomes the attributes key for each resource in the collection.
id (list(str), optional) – The optional id for the resource; if provided this becomes the id key for each resource in the collection.

Returns

A dictionary representing the JsonApi document with data as the top-level key, which itself contains a list of resources.

Return type

dict

Raises

ValueError – If the number of elements in attributes_list differs from the number of elements in ids_list.

static jsonapi_document(type, attributes, id=None)[source]¶

Return a JsonApi document with a single resource.

A JsonApi document has the following structure:

{
    "data": {
        "type": "...",
        "id": "...",  // Optional
        "attributes": {
            "...": "...",
            ...
        }
    }
}

Parameters

type (str) – The type of resource; this becomes the type key in the data element.
attributes (dict) – The attributes for this resource; this becomes the attributes key in the data element.
id (str, optional) – The optional id for the resource; if provided this becomes the id key in the data element.

Returns

A dictionary representing the JsonApi document with data as the top-level key, which itself contains a single resource.

Return type

dict

classmethod set_default_session_class(session_class)[source]¶

Set the default session class for JsonApiService.

The default session is used for any JsonApiService that is instantiated without specifying the session class.

Parameters: session_class (class) – The session class to use when instantiating the session. This must be the class JsonApiSession itself or a derived class from JsonApiSession.

property session¶

The session instance used by this service.

Type: Session

property token¶

The bearer token used in the requests.

Type: str

class ThirdPartyService(url='', session_class=None)[source]¶

The default Descartes Labs HTTP Service used for 3rd party servers.

This service has a default timeout and retry policy that retries HTTP requests depending on the timeout and HTTP status code that was returned. This is based on the requests timeouts and the urllib3 retry object.

The default timeouts are set to 9.5 seconds for establishing a connection (slightly larger than a multiple of 3, which is the TCP default packet retransmission window), and 30 seconds for reading a response.

The default retry logic retries up to 10 times total, a maximum of 2 for establishing a connection. The backoff_factor is a random number between 1 and 3, but will never be more than 2 minutes. The unexpected HTTP status codes that will be retried are 429, 500, 502, 503, and 504 for any of the HTTP requests. Here we specify 429s explicitly (unlike for the Service class) because we have no guarantee that third party services are consistent about providing a retry-after header.

Parameters

url (str) – The URL prefix to use for communication with the 3rd party server.
session_class (class) – The session class to use when instantiating the session. This must be a derived class from Session. If not provided, the default session class is used. You can register a default session class with ThirdPartyService.set_default_session_class().

Raises

TypeError – If you try to use a session class that is not derived from Session.

Methods:

`get_default_session_class`()	Get the default session class for the `ThirdPartyService`.
`set_default_session_class`([session_class])	Set the default session class for `ThirdPartyService`.

classmethod get_default_session_class()[source]¶

Get the default session class for the ThirdPartyService.

Returns: The default session class, which is Session itself or a derived class from Session.
Return type: Session

classmethod set_default_session_class(session_class=None)[source]¶

Set the default session class for ThirdPartyService.

The default session is used for any ThirdPartyService() that is instantiated without specifying the session class.

Parameters: session_class (class) – The session class to use when instantiating the session. This must be the class Session itself or a derived class from Session.

class Session(base_url, timeout=None)[source]¶

The HTTP Session that performs the actual HTTP request.

This is the base session that is used for all Descartes Labs HTTP calls which itself is derived from requests.Session.

You cannot control its instantiation, but you can derive from this class and pass it as the class to use when you instantiate a Service or register it as the default session class using Service.set_default_session_class().

Parameters

base_url (str) – The URL prefix to use for communication with the Descartes Labs servers.
timeout (int or tuple(int, int)) –
See requests timeouts.

Methods:

`handle_proxy_authentication`(method, url, …)	Handle proxy authentication when the HTTP request was denied.
`initialize`()	Initialize the `Session` instance
`request`(method, url, **kwargs)	Sends an HTTP request and emits Descartes Labs specific errors.

handle_proxy_authentication(method, url, **kwargs)[source]¶

Handle proxy authentication when the HTTP request was denied.

This method can be overridden in a derived class. By default a ProxyAuthenticationRequiredError will be raised.

Returns: Return True if the proxy authentication has been handled and no further exception should be raised. Return False if a ProxyAuthenticationRequiredError should be raised.
Return type: bool

initialize()[source]¶

Initialize the Session instance

You can override this method in a derived class to add your own initialization. This method does nothing in the base class.

request(method, url, **kwargs)[source]¶

Sends an HTTP request and emits Descartes Labs specific errors.

Parameters

method (str) – The HTTP method to use.
url (str) – The URL to send the request to.
kwargs (dict) – Additional arguments. See requests.request.

Returns

A request.Response object.

Return type

Response

Raises

BadRequestError – Either a 400 or 422 HTTP response status code was encountered.
NotFoundError – A 404 HTTP response status code was encountered.
ProxyAuthenticationRequiredError – A 407 HTTP response status code was encountered and the resulting handle_proxy_authentication() did not indicate that the proxy authentication was handled.
ConflictError – A 409 HTTP response status code was encountered.
RateLimitError – A 429 HTTP response status code was encountered.
GatewayTimeoutError – A 504 HTTP response status code was encountered.
ServerError – Any HTTP response status code larger than 400 that was not covered above is returned as a ServerError. The original HTTP response status code can be found in the attribute original_status.

class JsonApiSession(*args, **kwargs)[source]¶

Bases: descarteslabs.client.services.service.service.Session

The HTTP Session that performs the actual JSONAPI HTTP request.

You cannot control its instantiation, but you can derive from this class and pass it as the class to use when you instantiate a JsonApiService or register it as the default session class using JsonApiService.set_default_session_class().

Parameters

base_url (str) – The URL prefix to use for communication with the Descartes Labs servers.
timeout (int or tuple(int, int)) –
See requests timeouts.

Methods:

`handle_proxy_authentication`(method, url, …)	Handle proxy authentication when the HTTP request was denied.
`initialize`()	Initialize the `Session` instance
`request`(args, *kwargs)	Sends an HTTP request and emits Descartes Labs specific errors.

handle_proxy_authentication(method, url, **kwargs)[source]¶

Handle proxy authentication when the HTTP request was denied.

This method can be overridden in a derived class. By default a ProxyAuthenticationRequiredError will be raised.

Returns: Return True if the proxy authentication has been handled and no further exception should be raised. Return False if a ProxyAuthenticationRequiredError should be raised.
Return type: bool

initialize()[source]¶

Initialize the Session instance

You can override this method in a derived class to add your own initialization. This method does nothing in the base class.

request(*args, **kwargs)[source]¶

Sends an HTTP request and emits Descartes Labs specific errors.

Parameters

method (str) – The HTTP method to use.
url (str) – The URL to send the request to.
kwargs (dict) –
Additional arguments. See requests.request.

Returns

A request.Response object.

Return type

Response

Raises

BadRequestError – Either a 400 or 422 HTTP response status code was encountered.
NotFoundError – A 404 HTTP response status code was encountered.
ProxyAuthenticationRequiredError – A 407 HTTP response status code was encountered and the resulting handle_proxy_authentication() did not indicate that the proxy authentication was handled.
ConflictError – A 409 HTTP response status code was encountered.
RateLimitError – A 429 HTTP response status code was encountered.
GatewayTimeoutError – A 504 HTTP response status code was encountered.
ServerError – Any HTTP response status code larger than 400 that was not covered above is returned as a ServerError. The original HTTP response status code can be found in the attribute original_status.

Note

If rewrite_errors was set to True in the corresponding JsonApiService, the JSONAPI errors will be rewritten in a more human readable format.