Get told when files change in key folders

from google.oauth2.credentials import Credentials
from googleapiclient.discovery import build
from datetime import datetime, timezone
from clickruntime import on_trigger, report_fetched, credentials, state, notify

FOLDERS = {"client-uploads-folder-id": "Client uploads", "contracts-folder-id": "Contracts"}

@on_trigger
def run(event):
    drive = build("drive", "v3", credentials=Credentials(credentials.connection("google", "work")), cache_discovery=False)
    since = state.get("since") or datetime.now(timezone.utc).isoformat()
    now = datetime.now(timezone.utc).isoformat()
    lines = []
    for fid, label in FOLDERS.items():
        files = drive.files().list(q=f"'{fid}' in parents and modifiedTime > '{since}' and trashed = false",
                                   fields="files(name,createdTime,modifiedTime,lastModifyingUser,webViewLink)").execute()["files"]
        for f in files:
            what = "New" if f["createdTime"] > since else "Changed"
            who = f.get("lastModifyingUser", {}).get("displayName", "someone")
            lines.append(f"{what} in {label}: {f['name']} by {who}\n{f['webViewLink']}")
    report_fetched(len(lines))
    state.set("since", now)
    if lines:
        notify.email_me(f"{len(lines)} Drive files new or changed", "\n\n".join(lines))
    return {"files": len(lines)}