从 Python 客户端访问后端 API

如果要从 Python 客户端访问 Cloud Endpoints API，需要使用 Google API Python 客户端库。 如果 API 无需任何身份验证，则您的客户端可以访问 API，具体如以下示例代码所示：

import pprint

from googleapiclient.discovery import build


def main():
  # Build a service object for interacting with the API.
  api_root = 'https://guestbook.appspot.com/_ah/api'
  api = 'guestbook'
  version = 'v0.2'
  discovery_url = '%s/discovery/v1/apis/%s/%s/rest' % (api_root, api, version)
  service = build(api, version, discoveryServiceUrl=discovery_url)

  # Fetch all greetings and print them out.
  response = service.greetings().list().execute()
  pprint.pprint(response)

  # Fetch a single greeting and print it out.
  response = service.greetings().get(id='9001').execute()
  pprint.pprint(response)


if __name__ == '__main__':
  main()

在此示例代码中：

• api_root 是用于提供 API 方法的前端根网址。通常网址为 https://YOUR_PROJECT_ID.appspot.com/_ah/api，其中 YOUR_PROJECT_ID 表示您的 Google Cloud
• api 是 API 的名称。
• version 是后端 API 的版本。

访问需要身份验证的 API

如果后端 API 要求进行身份验证，则需同时使用 Google API Python 客户端库和 OAuth2.0 客户端库。

您的客户端可以使用类似以下形式的代码获取所需授权并访问 API：

import argparse
import pprint
import sys

from googleapiclient import discovery
import httplib2
import oauth2client
from oauth2client import tools


CLIENT_ID = 'YOUR_CLIENT_ID'
CLIENT_SECRET = 'YOUR_CLIENT_SECRET'
SCOPE = 'https://www.googleapis.com/auth/userinfo.email'
USER_AGENT = 'my-cmdline-tool/1.0'
OAUTH_DISPLAY_NAME = 'My Commandline Tool'


def main(argv):
  # Parse command line flags used by the oauth2client library.
  parser = argparse.ArgumentParser(
      description='Auth sample',
      formatter_class=argparse.RawDescriptionHelpFormatter,
      parents=[tools.argparser])
  flags = parser.parse_args(argv[1:])

  # Acquire and store oauth token.
  storage = oauth2client.file.Storage('guestbook.dat')
  credentials = storage.get()

  if credentials is None or credentials.invalid:
    flow = oauth2client.client.OAuth2WebServerFlow(
        client_id=YOUR_CLIENT_ID,
        client_secret=YOUR_CLIENT_SECRET,
        scope=SCOPE,
        user_agent=USER_AGENT,
        oauth_displayname=OAUTH_DISPLAY_NAME)
    credentials = tools.run_flow(flow, storage, flags)
  http = httplib2.Http()
  http = credentials.authorize(http)

  # Build a service object for interacting with the API.
  api_root = 'https://guestbook.appspot.com/_ah/api'
  api = 'guestbook'
  version = 'v0.2'
  discovery_url = '%s/discovery/v1/apis/%s/%s/rest' % (api_root, api, version)
  service = discovery.build(
      api, version, discoveryServiceUrl=discovery_url, http=http)

  # Fetch all greetings and print them out.
  response = service.greetings().list().execute()
  pprint.pprint(response)

  # Fetch a single greeting and print it out.
  response = service.greetings().get(id='9001').execute()
  pprint.pprint(response)


if __name__ == '__main__':
  main(sys.argv)

请注意，必须按所示方式设置 SCOPE。如需了解 YOUR_CLIENT_ID 和 YOUR_CLIENT_SECRET，请参阅创建客户端 ID。