来自Google Cloud Client Libraries官方文档：https://googlecloudplatform.g...

from google.cloud import translate
client = translate.Client()
client.translate(['Me llamo Jeff', 'My name is Jeff'],target_language='de')

代码执行结果：

C:\Python27\lib\site-packages\google\auth\_default.py:66: UserWarning: Your application has authenticated using end user
 credentials from Google Cloud SDK. We recommend that most server applications use service accounts instead. If your app
lication continues to use end user credentials from Cloud SDK, you might receive a "quota exceeded" or "API not enabled"
 error. For more information about service accounts, see https://cloud.google.com/docs/authentication/.
  warnings.warn(_CLOUD_SDK_CREDENTIALS_WARNING)
Traceback (most recent call last):
  File "C:\Code\Google\test\run.py", line 15, in <module>
    target_language=target)
  File "C:\Python27\lib\site-packages\google\cloud\translate_v2\client.py", line 233, in translate
    method='POST', path='', data=data)
  File "C:\Python27\lib\site-packages\google\cloud\_http.py", line 293, in api_request
    raise exceptions.from_http_response(response)
google.api_core.exceptions.Forbidden: 403 POST https://translation.googleapis.com/language/translate/v2: Your applicatio
n has authenticated using end user credentials from the Google Cloud SDK or Google Cloud Shell which are not supported b
y the translate.googleapis.com. We recommend that most server applications use service accounts instead. For more inform
ation about service accounts and how to use them in your application, see https://cloud.google.com/docs/authentication/.

而如果在cmd下执行的话，可以正常执行

>>> from google.cloud import translate
>>> client = translate.Client()
>>> client.translate(['Me llamo Jeff', 'My name is Jeff'],target_language='de')
[{u'translatedText': u'Mein Name ist Jeff', 'input': 'Me llamo Jeff', u'detected
SourceLanguage': u'es'}, {u'translatedText': u'Mein Name ist Jeff', 'input': 'My
 name is Jeff', u'detectedSourceLanguage': u'en'}]