wxpython

[joe jacob]

On Jan 24, 4:20 pm, Tim Golden <m... at timgolden.me.uk> wrote:
> [Tim Golden]
>
>
>
> >> wxPython is trying to interpret your byte stream as a Unicode
> >> text stream encoded as cp1252. But it's not, so it gives up
> >> in a heap. One solution is to pass the repr of file_content.
> >> Another solution is for you to prefilter the text, replacing
> >> non-printables by their hex value or by some marker. Not much
> >> in it, really.
>
> >> <code>
> >> import random
> >> file_content = "".join (
> >>    chr (random.randint (0, 255)) for i in range (1000)
> >> )
> >> munged_text = "".join (
> >>    c if 32 <= ord (c) <= 126 else hex (ord (c)) for c in file_content
> >> )
>
> >> print repr (file_content)
> >> print munged_text
> >> </code>
>
> >> TJG
>
> [joe jacob]
>
> > If I open an exe file in notepad, I can see some junk characters. I'm
> > trying to develop a program like an editor which can encrypt a file
> > opened by it. I need to open files like exe or jpeg etc in the editor
> > and after encryption the encrypted data should be displayed in the
> > editor. I developed the editor but when I tried to open an windows exe
> > file in it I am getting the above mentioned error as the characters
> > contained in it are non unicode.
>
> Hi, Joe. I've copied this back to the list (and I encourage you to
> do the same when replying) since the more people see the issue,
> the more chances you've got of a useful answer!
>
> To try to address what you're saying here: notepad.exe makes some
> choice or other when confronted by the byte stream in a file which
> you open. I don't know what that choice is, or how it tries to cope
> with encoded unicode text, but whatever it does by the choice of
> its developers. The "some junk characters" are one of several
> possible representations of the not-ordinary-characters which your
> file contains.
>
> If you're writing your own editor or file display, you have to make
> similar choices, which includes understanding what possibilities are
> offered by the toolset you're employing -- in this case, wxPython.
>
> <slight guesswork - I haven't checked the source>
> The wxPython wx.TextCtrl expects to be fed with Unicode text. If
> you pass it a string instead, it tries to decode it according to
> the system's default encoding, here cp1252. If it can't, it doesn't
> display "junk characters": it just gives an error.
> </slight guesswork>
>
> If you want junk characters, then you'll either have to explicitly
> pass in the characters you want displayed or do the kind of thing
> I suggested above to indicate their hex value, or find another
> control (or an option of the wx.TextCtrl) which will attempt to do
> the work for you when displaying raw bytes.
>
> I'm afraid I'm not a wxPython expert so maybe someone else has
> suggestions. But the most important thing is that you understand
> what's happening here and why you can't just say "I want it to
> do what Notepad does".
>
> TJG

Thanks for the information. I'll try to manage it some how.