如何使用 Python 与 BigQuery 建立连接

Question

我是 python 新手，我用过这段代码

from google.cloud import bigquery
from google.cloud.bigquery import  SchemaField


client = bigquery.Client(project='xxxxxxxxxxxxx')

我收到了这个错误

C:\Python27\python.exe "C:/Users/Vikas Chauhan/python_programs/bigQuery.py"
Traceback (most recent call last):
  File "C:/Users/Vikas Chauhan/python_programs/bigQuery.py", line 5, in <module>
    client = bigquery.Client(project='stellar-display-145814')
  File "C:\Python27\lib\site-packages\google\cloud\bigquery\client.py", line 83, in __init__
    project=project, credentials=credentials, _http=_http)
  File "C:\Python27\lib\site-packages\google\cloud\client.py", line 212, in __init__
    Client.__init__(self, credentials=credentials, _http=_http)
  File "C:\Python27\lib\site-packages\google\cloud\client.py", line 128, in __init__
    credentials = get_credentials()
  File "C:\Python27\lib\site-packages\google\cloud\credentials.py", line 39, in get_credentials
    credentials, _ = google.auth.default()
  File "C:\Python27\lib\site-packages\google\auth\_default.py", line 282, in default
    raise exceptions.DefaultCredentialsError(_HELP_MESSAGE)
google.auth.exceptions.DefaultCredentialsError: Could not automatically determine credentials. Please set GOOGLE_APPLICATION_CREDENTIALS or
explicitly create credential and re-run the application. For more
information, please see
https://developers.google.com/accounts/docs/application-default-credentials.

我已经设置了环境变量。我一次又一次地收到这个错误。

我是 python 新手，所以请帮我解决这个问题。我对此一无所知，即使用 python 与 bigquery 建立联系。 谢谢

Answer 1

首先，您需要一个google-api-client 的python 包。您可以使用 pip 安装它

pip install --upgrade google-api-python-client

然后设置指向您的服务帐户凭据的环境变量。如果您没有服务帐户，请创建一个新的服务帐户并将 json 凭据下载到您的本地。

GOOGLE_APPLICATION_CREDENTIALS=/path/to/credentials.json

现在一切都设置好了，写一段python代码就行了，

from apiclient import discovery
from oauth2client.client import GoogleCredentials

credentials = GoogleCredentials.get_application_default()
bq_client = discovery.build('bigquery', 'v2', credentials=credentials)

探索 BigQuery API 和 Google API Explorer。