I am building a Python project into a standalone executable using PyInstaller, and I’m encountering an issue when trying to run a Python script (fec.py) as a subprocess from the main script (main.py). Everything works fine when I run the program in my IDE, but when I compile it to an .exe, the subprocess call to fec.py fails and nothing happens

I have two Python files:

main.py: The main script that handles user input and calls fec.py via subprocess.
fec.py: A separate script that takes arguments and performs a task.
I’m using subprocess.Popen to run fec.py from main.py with arguments:

def run_download(self, args):
    try:
        # Handling paths when running as an executable
        if getattr(sys, 'frozen', False):
            bundle_dir = sys._MEIPASS  # Temp directory when packaged
        else:
            bundle_dir = os.path.dirname(os.path.abspath(__file__))  # Normal script location

        fec_script_path = os.path.join(bundle_dir, 'fec.py')

        # Debugging: Check if file exists
        if not os.path.exists(fec_script_path):
            raise FileNotFoundError(f"fec.py not found at {fec_script_path}")

        # Running the fec.py script
        process = subprocess.Popen([sys.executable, fec_script_path] + args, stdout=subprocess.PIPE,
                                   stderr=subprocess.PIPE, text=True)
        stdout, stderr = process.communicate()

        print(f"stdout: {stdout}")
        print(f"stderr: {stderr}")

    except Exception as e:
        print(f"Error: {str(e)}")```

How I am building the exe:
I am using this PyInstaller command to bundle both main.py and fec.py:

pyinstaller --noconfirm --onefile --console --add-data "C:UsershamzaOneDriveDokumenterinvoicefec.py;."