Python, Windows, Ansi - encoding, again

Question

Hello there,

even if i really tried... im stuck and somewhat desperate when it comes to Python, Windows, Ansi and character encoding. I need help, seriously... searching the web for the last few hours wasn't any help, it just drives me crazy.

I'm new to Python, so i have almost no clue what's going on. I'm about to learn the language, so my first program, which ist almost done, should automatically generate music-playlists from a given folder containing mp3s. That works just fine, besides one single problem...

...i can't write Umlaute (äöü) to the playlist-file.

After i found a solution for "wrong-encoded" Data in the sys.argv i was able to deal with that. When reading Metadata from the MP3s, i'm using some sort of simple character substitution to get rid of all those international special chars, like french accents or this crazy skandinavian "o" with a slash in it (i don't even know how to type it...). All fine.

But i'd like to write at least the mentioned Umlaute to the playlist-file, those characters are really common here in Germany. And unlike the Metadata, where i don't care about some missing characters or miss-spelled words, this is relevant - because now i'm writing the paths to the files.

I've tried so many various encoding and decoding methods, i can't list them all here.. heck, i'm not even able to tell which settings i tried half an hour ago. I found code online, here, and elsewhere, that seemed to work for some purposes. Not for mine.

I think the tricky part is this: it seems like the Problem is the Ansi called format of the files i need to write. Correct - i actually need this Ansi-stuff. About two hours ago i actually managed to write whatever i'd like to an UFT-8 file. Works like charm... until i realized that my Player (Winamp, old Version) somehow doesn't work with those UTF-8 playlist files. It couldn't resolve the Path, even if it looks right in my editor.

If i change the file format back to Ansi, Paths containing special chars get corrupted. I'm just guessing, but if Winamp reads this UTF-8 files as Ansi, that would cause the Problem i'm experiencing right now.

So...

1. I DO have to write äöü in a path, or it will not work
2. It DOES have to be an ANSI-"encoded" file, or it will not work
3. Things like line.write(str.decode('utf-8')) break the funktion of the file
4. A magical comment at the beginning of the script like # -*- coding: iso-8859-1 -*- does nothing here (though it is helpful when it comes to the mentioned Metadata and allowed characters in it...)
5. Oh, and i'm using Python 2.7.3. Third-Party modules dependencies, you know...

Is there ANYONE who could guide me towards a way out of this encoding hell? Any help is welcome. If i need 500 lines of Code for another functions or classes, i'll type them. If there's a module for handling such stuff, let me know! I'd buy it! Anything helpful will be tested.

Thank you for reading, thanks for any comment,

greets!

Answer 1

As mentioned in the comments, your question isn't very specific, so I'll try to give you some hints about character encodings, see if you can apply those to your specific case!

Unicode and Encoding

Here's a small primer about encoding. Basically, there are two ways to represent text in Python:

• unicode. You can consider that unicode is the ultimate encoding, you should strive to use it everywhere. In Python 2.x source files, unicode strings look like u'some unicode'.
• str. This is encoded text - to be able to read it, you need to know the encoding (or guess it). In Python 2.x, those strings look like 'some str'.

This changed in Python 3 (unicode is now str and str is now bytes).

How does that play out?

Usually, it's pretty straightforward to ensure that you code uses unicode for its execution, and uses str for I/O:

• Everything you receive is encoded, so you do input_string.decode('encoding') to convert it to unicode.
• Everything you need to output is unicode but needs to be encoded, so you do output_string.encode('encoding').

---

The most common encodings are cp-1252 on Windows (on US or EU systems), and utf-8 on Linux.

Applying this to your case

I DO have to write äöü in a path, or it will not work

Windows natively uses unicode for file paths and names, so you should actually always use unicode for those.

It DOES have to be an ANSI-"encoded" file, or it will not work

When you write to the file, be sure to always run your output through output.encode('cp1252') (or whatever encoding ANSI would be on your system).

Things like line.write(str.decode('utf-8')) break the funktion of the file

By now you probably realized that:

• If str as indeed an str instance, Python will try to convert it to unicode using the utf-8 encoding, but then try to encode it again (likely in ascii) to write it to the file
• If str is actually an unicode instance, Python will first encode it (likely in ascii, and that will probably crash) to then be able to decode it.

Bottom line is, you need to know if str is unicode, you should encode it. If it's already encoded, don't touch it (or decode it then encode it if the encoding is not the one you want!).

A magical comment at the beginning of the script like # -- coding: iso-8859-1 -- does nothing here (though it is helpful when it comes to the mentioned Metadata and allowed characters in it...)

Not a surprise, this only tells Python what encoding should be used to read your source file so that non-ascii characters are properly recognized.

Oh, and i'm using Python 2.7.3. Third-Party modules dependencies, you know...

Python 3 probably is a big update in terms of unicode and encoding, but that doesn't mean Python 2.x can't make it work!

Will that solve your issue?

You can't be sure, it's possible that the problem lies in the player you're using, not in your code.

Once you output it, you should make sure that your script's output is readable using reference tools (such as Windows Explorer). If it is, but the player still can't open it, you should consider updating to a newer version.