Python

from __future__ import print_function
import pickle
import os.path
from googleapiclient.discovery import build
from google_auth_oauthlib.flow import InstalledAppFlow
from google.auth.transport.requests import Request
import uuid
import time

# If modifying these scopes, delete the file token.pickle.
SCOPES = ['https://www.googleapis.com/auth/spreadsheets']

SPREADSHEET_ID = ''
LIST_NAME = ''
URL = ''
SAMPLE_RANGE_NAME = LIST_NAME + '!A1'
VALUE_INPUT_OPTION = 'USER_ENTERED'
LIMIT = 100000


def authorization():
    creds = None
    # The file token.pickle stores the user's access and refresh tokens, and is
    # created automatically when the authorization flow completes for the first
    # time.
    if os.path.exists('token.pickle'):
        with open('token.pickle', 'rb') as token:
            creds = pickle.load(token)
    # If there are no (valid) credentials available, let the user log in.
    if not creds or not creds.valid:
        if creds and creds.expired and creds.refresh_token:
            creds.refresh(Request())
        else:
            flow = InstalledAppFlow.from_client_secrets_file(
                'credentials.json', SCOPES)
            creds = flow.run_local_server()
        # Save the credentials for the next run
        with open('token.pickle', 'wb') as token:
            pickle.dump(creds, token)

    return build('sheets', 'v4', credentials=creds)


def add_img(limit, service):
    values = []
    data = []
    body = {
        'values': values
    }

    for request in range(limit):
        for number in range(20):
            data.append('=image("{0}?r={1}")'.format(URL, uuid.uuid4()))

        time.sleep(0.5)

        values.append(data)

        result = service.spreadsheets().values().update(
            spreadsheetId=SPREADSHEET_ID, range=SAMPLE_RANGE_NAME,
            valueInputOption=VALUE_INPUT_OPTION, body=body
        ).execute()

        data = []

        print('{0} cells updated.'.format(result.get('updatedCells')))


def main():
    service = authorization()
    add_img(LIMIT, service)


if __name__ == '__main__':
    main()