Get last month's ledger as CSV

import csv, io
from datetime import date, timedelta
from clickruntime import on_trigger, credentials, http, notify

REALM_ID = "1234567890"
API = f"https://quickbooks.api.intuit.com/v3/company/{REALM_ID}"

def qb(method, path, **kw):
    headers = {"Authorization": f"Bearer {credentials.connection('quickbooks', 'company')}", "Accept": "application/json"}
    resp = http.request(method, f"{API}{path}", headers=headers, params={"minorversion": 73, **kw.pop("params", {})}, **kw)
    resp.raise_for_status()
    return resp.json()

def query(sql):
    return qb("GET", "/query", params={"query": sql})["QueryResponse"]

def rows(section, out):
    for row in section.get("Row", []):
        if "ColData" in row:
            out.append([c.get("value", "") for c in row["ColData"]])
        rows(row.get("Rows", {}), out)
    return out

@on_trigger
def run(event):
    end = date.today().replace(day=1) - timedelta(days=1)
    span = {"start_date": end.replace(day=1).isoformat(), "end_date": end.isoformat()}
    gl = qb("GET", "/reports/GeneralLedger", params=span)
    invoices = query(f"select * from Invoice where TxnDate >= '{span['start_date']}' "
                     f"and TxnDate <= '{span['end_date']}' maxresults 1000").get("Invoice", [])
    buf = io.StringIO()
    w = csv.writer(buf)
    w.writerow([c["ColTitle"] for c in gl["Columns"]["Column"]])
    w.writerows(rows(gl["Rows"], []))
    w.writerows([[], ["Invoice", "Date", "Customer", "Total", "Balance"]])
    w.writerows([i["DocNumber"], i["TxnDate"], i["CustomerRef"]["name"], i["TotalAmt"], i["Balance"]] for i in invoices)
    notify.email_me(f"QuickBooks ledger {end:%B %Y}", buf.getvalue()[:100_000])
    return {"invoices": len(invoices)}