WMI Console opening and closing when running exe file created using python code and pyinstaller

Question

I have a python file as battery_perc.pyw:

import subprocess
import time
import pyttsx3

engine = pyttsx3.init()

def say_pc(txt):
    engine.say(txt)
    engine.runAndWait()

while True:
    say_pc(str(int(subprocess.run(["WMIC", "PATH", "Win32_Battery", "Get", "EstimatedChargeRemaining"], capture_output=True).stdout.decode().split("\n")[1][:3].strip())))
    time.sleep(10)

I created exe file using below:

pyinstaller --onefile --noconsole  'battery_perc.pyw'

When I am running the battery_perc.exe, it works but every 10 seconds WMI Console is opened and closed immediately, just like its blinking.