无需在Python中打开浏览器即可使用Gmail API

import os
import base64
from google.oauth2.credentials import Credentials
from google_auth_oauthlib.flow import InstalledAppFlow
from googleapiclient.discovery import build
from googleapiclient.errors import HttpError
from email.mime.multipart import MIMEMultipart
from email.mime.text import MIMEText
from email.mime.image import MIMEImage
from email.mime.base import MIMEBase
from email import encoders

# 定义要发送的邮件内容
sender = 'your-email@gmail.com'
receiver = 'recipient-email@example.com'
subject = 'Test Email'
message = 'This is a test email sent using Gmail API.'

# 定义附件文件路径
attachment_path = 'path/to/attachment.pdf'

# 定义Gmail API的访问范围
SCOPES = ['https://www.googleapis.com/auth/gmail.compose']

# 通过OAuth2进行身份验证并获取凭据
def get_credentials():
    creds = None
    # 存储凭据的文件路径
    token_file = 'path/to/token.json'
    # 存储OAuth2客户端密钥的文件路径
    credentials_file = 'path/to/credentials.json'
    
    if os.path.exists(token_file):
        creds = Credentials.from_authorized_user_file(token_file, SCOPES)
    
    # 如果没有有效的凭据，则从客户端密钥文件进行身份验证
    if not creds or not creds.valid:
        flow = InstalledAppFlow.from_client_secrets_file(credentials_file, SCOPES)
        creds = flow.run_local_server(port=0)
        # 保存凭据以便下次使用
        with open(token_file, 'w') as token:
            token.write(creds.to_json())
    
    return creds

def create_message(sender, receiver, subject, message, attachment_path=None):
    msg = MIMEMultipart()
    msg['From'] = sender
    msg['To'] = receiver
    msg['Subject'] = subject

    msg.attach(MIMEText(message, 'plain'))
    
    if attachment_path:
        with open(attachment_path, 'rb') as attachment:
            part = MIMEBase('application', 'octet-stream')
            part.set_payload(attachment.read())
        encoders.encode_base64(part)
        part.add_header('Content-Disposition', f'attachment; filename="{os.path.basename(attachment_path)}"')
        msg.attach(part)
    
    return {'raw': base64.urlsafe_b64encode(msg.as_bytes()).decode()}

def send_message(service, user_id, message):
    try:
        message = service.users().messages().send(userId=user_id, body=message).execute()
        print('Message sent successfully.')
    except HttpError as error:
        print(f'An error occurred: {error}')

# 获取凭据
credentials = get_credentials()

# 创建Gmail API服务
service = build('gmail', 'v1', credentials=credentials)

# 创建邮件消息
message = create_message(sender, receiver, subject, message, attachment_path)

# 发送邮件
send_message(service, 'me', message)