This document provides all the basic information you need to start using the library. It covers important library concepts, shows examples for various use cases, and gives links to more information.
There are a few setup steps you need to complete before you can use this library:
It is important to understand the basics of how API authentication and authorization are handled. All API calls must use either simple or authorized access (defined below). Many API methods require authorized access, but some can use either. Some API methods that can use either behave differently, depending on whether you use simple or authorized access. See the API's method documentation to determine the appropriate access type.
These API calls do not access any private user data. Your application must authenticate itself as an application belonging to your Google Cloud project. This is needed to measure project usage for accounting purposes.
API key: To authenticate your application, use an API key for your Google Cloud Console project. Every simple access call your application makes must include this key.
Warning: Keep your API key private. If someone obtains your key, they could use it to consume your quota or incur charges against your Google Cloud project.
These API calls access private user data. Before you can call them, the user that has access to the private data must grant your application access. Therefore, your application must be authenticated, the user must grant access for your application, and the user must be authenticated in order to grant that access. All of this is accomplished with OAuth 2.0 and libraries written for it.
Scope: Each API defines one or more scopes that declare a set of operations permitted. For example, an API might have read-only and read-write scopes. When your application requests access to user data, the request must include one or more scopes. The user needs to approve the scope of access your application is requesting.
Refresh and access tokens: When a user grants your application access, the OAuth 2.0 authorization server provides your application with refresh and access tokens. These tokens are only valid for the scope requested. Your application uses access tokens to authorize API calls. Access tokens expire, but refresh tokens do not. Your application can use a refresh token to acquire a new access token.
Warning: Keep refresh and access tokens private. If someone obtains your tokens, they could use them to access private user data.
Client ID and client secret: These strings uniquely identify your application and are used to acquire tokens. They are created for your Google Cloud project on the API Access pane of the Google Cloud. There are several types of client IDs, so be sure to get the correct type for your application:
Warning: Keep your client secret private. If someone obtains your client secret, they could use it to consume your quota, incur charges against your Google Cloud project, and request access to user data.
This section describes how to build an API-specific service object, make calls to the service, and process the response.
Whether you are using simple or authorized API access, you use the build() function to create a service object. It takes an API name and API version as arguments. You can see the list of all API versions on the Supported APIs page. The service object is constructed with methods specific to the given API. To create it, do the following:
from googleapiclient.discovery import build service = build('api_name', 'api_version', ...)
Each API service provides access to one or more resources. A set of resources of the same type is called a collection. The names of these collections are specific to the API. The service object is constructed with a function for every collection defined by the API. If the given API has a collection named stamps, you create the collection object like this:
collection = service.stamps()
It is also possible for collections to be nested:
nested_collection = service.featured().stamps()
Every collection has a list of methods defined by the API. Calling a collection's method returns an HttpRequest object. If the given API collection has a method named list that takes an argument called cents, you create a request object for that method like this:
request = collection.list(cents=5)
Creating a request does not actually call the API. To execute the request and get a response, call the execute() function:
response = request.execute()
Alternatively, you can combine previous steps on a single line:
response = service.stamps().list(cents=5).execute()
The response is a Python object built from the JSON response sent by the API server. The JSON structure is specific to the API; for details, see the API's reference documentation. You can also simply print the JSON to see the structure:
import json ... print json.dumps(response, sort_keys=True, indent=4)
For example, if the printed JSON is the following:
{ "count": 2, "items": [ { "cents": 5, "name": "#586 1923-26 5-cent blue Theodore Roosevelt MLH perf 10" }, { "cents": 5, "name": "#628 1926 5-cent Ericsson Memorial MLH" } ] }
You can access the data like this:
print('Num 5 cent stamps: %d'.format(response['count'])) print('First stamp name: %s'.format(response['items'][0]['name']))
Use the APIs Explorer to browse APIs, list available methods, and even try API calls from your browser.
Core library documentation. and Library reference documentation by API. is available.