使用 google API 发送电子邮件时出现“unauthorized_client”错误

Question

运行代码时出现此错误：

google.auth.exceptions.RefreshError: ('unauthorized_client: 客户端未经授权无法使用此方法检索访问令牌，或客户端未获得任何请求范围的授权。', {'error': 'unauthorized_client' , 'error_description': '客户端未授权使用此方法检索访问令牌，或客户端未授权任何请求的范围。'})

代码如下：

from __future__ import print_function
from googleapiclient import discovery, errors
from oauth2client import file, client, tools
from google.oauth2 import service_account
from email.mime.text import MIMEText
import base64

SERVICE_ACCOUNT_FILE = 'keys.json'
SCOPES = [' https://www.googleapis.com/auth/gmail.send']

# The user we want to "impersonate"
USER_EMAIL = "myName@myDomain.com"


def validationService():
    # Set the crendentials
    credentials = service_account.Credentials. \
        from_service_account_file(SERVICE_ACCOUNT_FILE, scopes=SCOPES)
    # Delegate the credentials to the user you want to impersonate
    delegated_credentials = credentials.with_subject(USER_EMAIL)
    service = discovery.build('gmail', 'v1', credentials=delegated_credentials)
    return service

def send_message(service):
    gmail_from = 'myName@myDomain.com'
    gmail_to = 'anotherName@gmail.com'
    gmail_subject = 'Hello World'
    gmail_content = 'test test'

    message = MIMEText(gmail_content)
    message['to'] = gmail_to
    message['from'] = gmail_from
    message['subject'] = gmail_subject
    raw = base64.urlsafe_b64encode(message.as_bytes())
    raw = raw.decode()
    body = {'raw': raw}

    try:
        message = (service.users().messages().send(userId='me', body=body)
                   .execute())
        print('your message has been sent')
        return message
    except errors.HttpError as error:
        print('An error occurred: %s' % error)


send_message(validationService())

我不明白我的电子邮件地址“gmail_from”在代码中的哪个位置与我的电子邮件地址相关联。除此之外，我还可以在 gmail 中访问我的 IDE：

我还在 google 控制台中创建了 OAuth 2.0 客户端 ID 凭据和服务帐户凭据，但我并不真正了解如何/在何处使用这些凭据。

我错过了什么？

在 google 网站上：https://developers.google.com/identity/protocols/oauth2/service-account#error-codes 我发现我需要“在管理控制台的域范围委派页面中，删除客户端，然后使用数字 ID 重新添加它。”但我不明白该怎么做，也不知道这有什么帮助。

Answer 1

范围内多了一个空格：

SCOPES = [' https://www.googleapis.com/auth/gmail.send']
           ^ here