Find leads with missing details or duplicates

from collections import defaultdict
from clickruntime import on_trigger, credentials, http, notify

@on_trigger
def run(event):
    h = {"Authorization": f"Zoho-oauthtoken {credentials.connection('zoho', 'work')}"}
    leads, token = [], None
    while True:
        params = {"fields": "Full_Name,Email,Phone,Lead_Source", "per_page": 200, **({"page_token": token} if token else {})}
        r = http.get("https://www.zohoapis.com/crm/v8/Leads", params=params, headers=h)
        if r.status_code == 204:
            break
        leads += r.json()["data"]
        token = r.json()["info"].get("next_page_token")
        if not r.json()["info"]["more_records"]:
            break
    missing = [f"  {l['Full_Name']}: missing " + ", ".join(f for f in ("Email", "Phone", "Lead_Source") if not l.get(f))
               for l in leads if not all(l.get(f) for f in ("Email", "Phone", "Lead_Source"))]
    by_email = defaultdict(list)
    for l in leads:
        if l.get("Email"):
            by_email[l["Email"].lower()].append(l["Full_Name"])
    dupes = [f"  {e}: {', '.join(n)}" for e, n in by_email.items() if len(n) > 1]
    notify.email_me("Zoho CRM lead data check",
                    f"Missing fields ({len(missing)}):\n" + "\n".join(missing) + f"\n\nShared emails ({len(dupes)}):\n" + "\n".join(dupes))
    return {"missing": len(missing), "duplicates": len(dupes)}