is excel open? if not open it!

excel.py

from win32com.client import Dispatch
import subprocess
import socket_client

def openExcel(workbook):
    xl = Dispatch("Excel.Application")
    xl.visible = True
    wb = xl.Workbooks.Open(workbook)

def checkOpenApp(appname):
    cmd = subprocess.Popen('tasklist', shell=True, stdout=subprocess.PIPE)
    for line in cmd.stdout:
        if appname in line:
            return True
            
def isok():
    """
    Checks if Excel is open, if not opens relevant workbook
    """
    wbk_to_open = 'C:\Users\B8694209\Desktop\uptime\client test.xlsb'
    if not checkOpenApp('EXCEL.EXE'):
        socket_client.sendMessage('Excel not open!')
        openExcel(wbk_to_open)
        isok()
    else:
        socket_client.sendMessage("Workbook open")

if __name__ == '__main__':
    isok()