WARNING: WatchFiles detected changes in 'serial_data_handle V1_in.py'. Reloading... .Got stucked here

[v479038280]

Question

What kind of behavior would prevent NiceGUI from refreshing and keep it stuck at "Reloading..." after detecting changes in 'serial_data_handle V1_in.py' with WatchFiles?

I have to close the terminal from windows task manager center,

[rodja]

Most often you have some other process running which is not properly shut down when uvicorn tries to reload. Please provide a minimum reproducible code example. This would allow us and the community to help more efficiently. Thanks!

[v479038280]

Here is the code

import serial
import re
import os
from pathlib import Path
import asyncio
import datetime

from nicegui import app, run, ui

import pymodbus.client as ModbusClient
from pymodbus.payload import BinaryPayloadBuilder
from pymodbus.constants import Endian

from pymodbus import (
    ExceptionResponse,
    FramerType,
    ModbusException,
    pymodbus_apply_logging_config,
)
from pymodbus.exceptions import ConnectionException


log=None
mb_client=None



log = ui.log().classes('w-full h-full')


async def read_loop() -> None:
    global ser,mb_client,log 
    while not app.is_stopped:
        try:
            ser = serial.Serial('COM8',19200,timeout=5)
            mb_client = ModbusClient.AsyncModbusTcpClient('127.0.0.1',port=502)
            await mb_client.connect() 
            await asyncio.sleep(0.1)
            print(f'modbus client connected at time {datetime.datetime.now()}')   
            print(f'serial opened at time {datetime.datetime.now()}')
            i=0
            while ser.is_open and mb_client.connected:
                try:
                    line =await run.io_bound(lambda:(ser.read(50)))
                    await asyncio.sleep(0.01)
                    if line:
                        data=line.decode('ascii')
                        print(f'data {data}')
                        match = re.search(r'#.*?&', data) 
                        if match is not None:
                            match=match.group()
                            print(f'match  {match}')
                            match=match[1:15]
                            temp_store=None
                            if match != temp_store:
                                temp_store=match
                                i=i+1
                                if 'abc' in match:
                                    log.push(f'{i}:{match} - {datetime.datetime.now()}')
                                    builder = BinaryPayloadBuilder(byteorder=Endian.BIG, wordorder=Endian.LITTLE)
                                    builder.add_32bit_int(62000)
                                    tagvalue = builder.to_registers()
                                    await mb_client.write_registers(5122,tagvalue)
                                    print(f'send abc TO device at {datetime.datetime.now()}')
                                                             
                            mb_client.close()
                            print(f'Serial closed at time {datetime.datetime.now()},78')
                            print(f'Modbus closed at time {datetime.datetime.now()}, 78')
                            await asyncio.sleep(0.1)
                            i=i+1
                            
                except Exception as exc:
                    mb_client.close()
                    ser.close()
                    print('Serial and closed 115')
                    break
             
        
        except Exception as exc:
            mb_client.close()
            ser.close()
            print('Serial and closed 122')
            continue
            
        mb_client.close()   
        ser.close()
        print(f'Serial closed at time {datetime.datetime.now()},129')
        print(f'Modbus closed at time {datetime.datetime.now()} 129')

app.on_startup(read_loop)

ui.run(favicon='🗀',title='abctest',reload=False)

[falkoschindler]

• Sorry, @v479038280, this code is far from minimal. Is it really important how serial input is processed and which specific message is sent back? Are all try-except blocks necessary to reproduce the problem? Let alone all these unused imports...
• And the code is not reproducible without having access to your port COM8 and the connected hardware.
• Last but not least, reload=False doesn't match your problem description that something is trying to reload.

Anyway, I wonder if the inner while loop is preventing the app from terminating, because it doesn't check for app.is_stopped. And there's also the state app.is_stopping, which might be worth checking too.

[v479038280]

I should add app.is_stop to the inner while.Thank you