在 Python 项目中设置 GOOGLE_APPLICATION_CREDENTIALS 以使用 Google API

Question

我是一名编程初学者，我正在努力学习如何将谷歌 API 与 Python 一起使用。

我有：

1. 在 Google Cloud 上创建了一个项目并启用了我想要使用的 API，Natural Language API。
2. 创建凭证并下载凭证JSON文件，保存为apikey.JSON
3. 在终端中我运行了这个命令：export GOOGLE_APPLICATION_CREDENTIALS=apikey.JSON，没有弹出错误。

但是，即使我为此运行了最简单的代码，我也会遇到错误，提示找不到凭据变量。

我不知道现在该做什么。请帮忙。

这是我的代码：

from google.cloud import language

def sentiment_text(text):

    client = language.LanguageServiceClient()

    sentiment = client.analyze_sentiment(text).document_sentiment

    print('Score: {}'.format(sentiment.score))
    print('Magnitude: {}'.format(sentiment.magnitude))

sampletxt='Python is great'

sentiment_text(sampletxt)

我有错误：

> Traceback (most recent call last):   File
> "/Users/YELI1/Downloads/googlecloud/sentimentanalysis/simple.py", line
> 21, in <module>
>     sentiment_text(sampletxt)
> 
>   File
> "/Users/YELI1/Downloads/googlecloud/sentimentanalysis/simple.py", line
> 5, in sentiment_text
>     client = language.LanguageServiceClient()
> 
>   File
> "/usr/local/lib/python3.6/site-packages/google/cloud/gapic/language/v1/language_service_client.py",
> line 147, in __init__
>     ssl_credentials=ssl_credentials)
> 
>   File "/usr/local/lib/python3.6/site-packages/google/gax/grpc.py",
> line 106, in create_stub
> 
>     credentials = _grpc_google_auth.get_default_credentials(scopes)   File
> "/usr/local/lib/python3.6/site-packages/google/gax/_grpc_google_auth.py",
> line 62, in get_default_credentials
>     credentials, _ = google.auth.default(scopes=scopes)
> 
>   File
> "/usr/local/lib/python3.6/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.

值不在环境中

import os 
print(os.environ['GOOGLE_APPLICATION_CREDENTIALS']) 
   File "/usr/local/Cellar/python3/3.6.2/Frameworks/Python.framework‌​/Versions/3.6/lib/py‌​thon3.6/os.py", line 669, in getitem  
raise KeyError(key) from None KeyError: 'GOOGLE_APPLICATION_CREDENTIALS'

Answer 1

如果您正在使用 jupyter 笔记本并希望在 Python 代码中设置 GOOGLE_APPLICATION_CREDENTIALS 环境变量：

import os
os.environ["GOOGLE_APPLICATION_CREDENTIALS"]="/path/to/file.json"

Answer 2

我知道这篇文章已得到答复，但以下是指定 GOOGLE_APPLICATION_CREDENTIALS 变量的更简洁的方法。

client = language.LanguageServiceClient.from_service_account_json("/path/to/file.json")

Answer 3

还有一种更简单的方法可以通过明确提及凭据并将其传递给客户端来使其工作，如下所示。

import os
from google.oauth2 import service_account

credentials = service_account.Credentials.from_service_account_file("your-json-path-with-filename.json")
client = language.LanguageServiceClient(credentials=credentials)

Answer 4

如果您在内存中有凭据（例如环境变量），并且您不想专门为它创建文件：

from google.cloud import storage
from google.oauth2 import service_account

gcp_json_credentials_dict = json.loads(gcp_credentials_string)
credentials = service_account.Credentials.from_service_account_info(gcp_json_credentials_dict)
client = storage.Client(project=gcp_json_credentials_dict['project_id'], credentials=credentials)

使用python3.7和google-cloud-storage==1.35.0

Answer 5

另一种测试方法是进入终端并输入：

# Linux/Unix
set | grep GOOGLE_APPLICATION_CREDENTIALS 

或

# Windows:
set | Select-String -Pattern GOOGLE_APPLICATION_CREDENTIALS 

这将显示环境变量及其所在的路径。如果这不返回任何内容，那么您还没有设置变量，或者您可能设置了错误的路径