python - Pyinstaller app is accessing txt files, but not writing to them (works before app compilation)

Question

settings.txt is stored and accessed within the compiled single file app, but it's not being written to. This works prior to Pyinstaller compilation when the file is in the same directory as the script.

The app is compiled from the terminal:

pyinstaller script.spec script.py --windowed --onefile

a.datas is set in the spec file as:

a.datas += [(‘settings.txt’,’/path/to/settings.txt’, "DATA”)]

and the file is read properly within the app:

with open(resource_path('settings.txt'), 'r') as f2

However, the file isn’t updated when attempting to overwrite the file:

def OnExit(self, event):
    with open(resource_path('settings.txt'), 'w') as f2:
        f2.write('update')

    self.Destroy()

resource_path is defined as:

def resource_path(relative_path):
    """ Get absolute path to resource, works for dev and for PyInstaller """
    try:
        # PyInstaller creates a temp folder and stores path in _MEIPASS
        base_path = sys._MEIPASS
    except Exception:
        base_path = os.environ.get("_MEIPASS2", os.path.abspath("."))

    return os.path.join(base_path, relative_path)

Answer 1

If you are on Windows, _MEIPASS returns the "short" name for the path in case that any component of it is more than 8 characters long. So, to test that this is the issue, try to make it a one-folder frozen app and then move it in a simple and short path: e.g., C:/test.

If this is the issue, you can workaround the problem by retrieving the long path using something like:

if hasattr(sys, '_MEIPASS'):
    import win32api
    sys_meipass = win32api.GetLongPathName(sys._MEIPASS)