Get yesterday's totals every morning

from google.oauth2.credentials import Credentials
from googleapiclient.discovery import build
from collections import defaultdict
from datetime import date, timedelta
from clickruntime import on_trigger, credentials, notify

SHEET_ID = "your-spreadsheet-id"

@on_trigger
def run(event):
    sheets = build("sheets", "v4", credentials=Credentials(credentials.connection("google", "work")), cache_discovery=False).spreadsheets()
    rows = sheets.values().get(spreadsheetId=SHEET_ID, range="Sales!A2:C").execute().get("values", [])
    y, d2 = (date.today() - timedelta(days=1)).isoformat(), (date.today() - timedelta(days=2)).isoformat()
    totals = {y: defaultdict(float), d2: defaultdict(float)}
    for day, product, amount in (r for r in rows if len(r) > 2):
        if day in totals:
            totals[day][product] += float(amount)
    lines = [f"{p}: {v:,.2f} ({v - totals[d2].get(p, 0):+,.2f} vs day before)" for p, v in sorted(totals[y].items())]
    total = sum(totals[y].values())
    notify.email_me(f"Sales {y}: {total:,.2f}", "\n".join(lines) or "No sales yesterday.")
    return {"total": total}