Google驱动器Python上传文件不起作用

我正在使用下面的代码，正在生成fileID，但未上传文件。我尝试调试，但它显示的输出与代码输出相同。我已将服务帐户json文件和test.csv放置在放置python代码的文件夹中。

from google.oauth2 import service_account
from googleapiclient.discovery import build
from googleapiclient.http import MediaFileUpload




def uploadGdrive():
    SCOPES = ['https://www.googleapis.com/auth/drive.file']
    SERVICE_ACCOUNT_FILE = './iron-tea-266706-8a1f9ee69710.json'
    folder_id = '15xc7s-dFnpW6pjtjtUH4kT1BnZ46ffFh'
    #file_id = '1IcbtXGW1ZMmv64SqqXJZCsFrwMlE3NiQcDZR98XuFX8'
    file_location='./test.csv'

    creds = service_account.Credentials.from_service_account_file(SERVICE_ACCOUNT_FILE, scopes=SCOPES)
    service = build('drive', 'v3', credentials=creds)
    file_metadata = {
        'name': 'Master Summary',
        'mimeType': 'application/vnd.google-apps.spreadsheet'
    }

    media = MediaFileUpload(
        '{}'.format(file_location),
        mimetype='text/csv',
        resumable=True)

    #This is to update existing file
    #file = service.files().update(body=file_metadata,media_body=media,fileId='{}'.format(file_id)).execute()
    #print(file.get('id'))

    #this is to create new  file
    file = service.files().create(body=file_metadata,
                                   media_body=media,
                                   fields='id').execute()
    print('File ID: %s' % file.get('id'))

if __name__ == '__main__':
    uploadGdrive()