Return type of QLineEdit:text

buhtz

I wonder what QLineEdit.text returns?

https://doc.qt.io/qt-6/qlineedit.html#text-prop

It seems to be a QString. But based on that Issue it sometimes returns a str instance.

How can I know?

Was there a change between Qt versions?

JonB

@buhtz
It has always been the case that PyQt and/or PySide convert freely between QString and Python str for you. (PyQt at least does not have a QString type, IIRC.) Same with some other types....

buhtz

@JonB said in Return type of QLineEdit:text:

It has always been the case that PyQt and/or PySide convert freely between QString and Python str for you.

Mhm... This confuses me much more. :D

In the Issue I was linking there is this line of Python code

diff_cmd = str( self.edit_command.text().toUtf8() )

The reported error was "str doesn't have toUtf8()". The Issue was reported in 2018 and never fixed. But the application (incl. this toUtf8()) was released more then once since 2018 and today.

I can't explain that to myself. Maybe it is about a new Qt or PyQt version?

I am scared to break the code. And without knowing much more about it I have to do some real tests using older Linux distros if this would break anything.

buhtz

So please don't waste more of your time here.

After some more research I assume that the dialog using this "buggy" code was rarely or never used by the users (for years). That is why the bug could live in the released code.

JonB

@buhtz
Don't quote me on this, but Python has encode('utf-8'), e.g. https://www.programiz.com/python-programming/methods/string/encode. Maybe you could do it that side? I have never understood encoding, despite asking many times and people explaining I just find it confusing! You may need an encoding expert who also does Python, maybe @SGaist will see this, if he doesn't mind he may be able to comment.

buhtz

@JonB Thanks for the hint. But since Python 3 there is no real need for encoding anymore. In most cases everything is utf-8 by default. But of course there are edge cases (e.g. default encoding when opening files on windows).

SGaist

Hi,

You likely have triggered something that either was never reported or a feature that was rarely used/triggered that it went unnoticed.

From memory, even in the PyQt4 time, the bindings would not provide QString not QByteArray. My guess is that the code was translated a bit too literally from a C++ example.