Push live shop-floor numbers into an open Excel dashboard (xlwings)

"""Push live shop-floor numbers into an already-open Excel workbook, once a
second - the "Excel front-end, Python back-end" pattern for a dashboard
nobody has to learn a new tool to read.

Usage:  python xlwings_dashboard.py
"""

import random
import time

import xlwings as xw

WORKBOOK_NAME = "dashboard.xlsx"   # must already be open in Excel
SHEET_NAME = "Dashboard"


def read_live_numbers():
    """Stand-in for a real data source (PLC tag, database, FOCAS poller...).
    Replace this with whatever actually produces your shop-floor numbers."""
    return {
        "parts_today": random.randint(280, 320),
        "scrap_today": random.randint(2, 12),
        "cycle_time_s": round(random.uniform(38, 45), 1),
        "machine_status": random.choice(["RUNNING", "RUNNING", "RUNNING", "HOLD"]),
    }


def main():
    wb = xw.Book(WORKBOOK_NAME)  # connects to the ALREADY OPEN workbook
    sheet = wb.sheets[SHEET_NAME]
    sheet["B6"].number_format = "@"  # Text - a time-like string would otherwise
                                      # get reinterpreted as an Excel time serial

    print(f"Connected to {WORKBOOK_NAME} / {SHEET_NAME}. Ctrl+C to stop.")
    try:
        while True:
            data = read_live_numbers()
            sheet["B2"].value = data["parts_today"]
            sheet["B3"].value = data["scrap_today"]
            sheet["B4"].value = data["cycle_time_s"]
            sheet["B5"].value = data["machine_status"]
            sheet["B6"].value = time.strftime("%H:%M:%S")
            time.sleep(1)
    except KeyboardInterrupt:
        print("\nStopped. The workbook keeps whatever it last showed.")


if __name__ == "__main__":
    main()