Get a weekly report of messy leads in Zoho CRM

import base64, re
from collections import defaultdict
from email.message import EmailMessage
from google.oauth2.credentials import Credentials
from googleapiclient.discovery import build
from clickruntime import on_trigger, credentials, http

ZOHO = "https://www.zohoapis.com/crm/v6"

@on_trigger
def run(event):
    zh = {"Authorization": f"Zoho-oauthtoken {credentials.connection('zoho', 'work')}"}
    leads, page, more = [], 1, True
    while more:
        resp = http.get(f"{ZOHO}/Leads", headers=zh, params={"fields": "Full_Name,Email,Company,Phone", "page": page, "per_page": 200}).json()
        leads, page, more = leads + resp.get("data", []), page + 1, resp.get("info", {}).get("more_records")
    issues, seen = [], defaultdict(list)
    for l in leads:
        email = (l.get("Email") or "").lower()
        if not re.fullmatch(r"[^@\s]+@[^@\s]+\.[a-z]{2,}", email):
            issues.append(f"Bad email: {l.get('Full_Name')} <{email}>")
        issues += [f"Missing {f}: {l.get('Full_Name')}" for f in ("Company", "Phone") if not l.get(f)]
        seen[email or f"{l.get('Full_Name')}|{l.get('Company')}"].append(l["Full_Name"])
    issues += [f"Duplicates: {', '.join(names)}" for names in seen.values() if len(names) > 1]
    msg = EmailMessage()
    msg["To"], msg["Subject"] = "me", f"Lead data quality: {len(issues)} issues"
    msg.set_content("\n".join(issues) or "All clean this week.")
    gmail = build("gmail", "v1", credentials=Credentials(credentials.connection("google", "work")), cache_discovery=False)
    gmail.users().messages().send(userId="me", body={"raw": base64.urlsafe_b64encode(msg.as_bytes()).decode()}).execute()
    return {"leads": len(leads), "issues": len(issues)}