How do I encode and decode this data to write to a file?

Dave Angel davea at davea.name
Mon Apr 29 07:46:51 EDT 2013


On 04/29/2013 05:47 AM, cl at isbd.net wrote:

A couple of generic comments:  your email program made a mess of the 
traceback by appending each source line to the location information.

Please mention your Python version & OS.  Apparently you're running 2.7 
on Linux or similar.

> I am debugging some code that creates a static HTML gallery from a
> directory hierarchy full of images. It's this package:-
>      https://pypi.python.org/pypi/Gallery2.py/2.0
>
>
> It's basically working and does pretty much what I want so I'm happy to
> put some effort into it and fix things.
>
> The problem I'm currently chasing is that it can't cope with directory
> names that have accented characters in them, it fails when it tries to
> write the HTML that creates the page with the thumbnails on.
>
> The code that's failing is:-
>
>          raw = os.path.join(directory, self.getNameNoExtension()) + ".html"
>          file = open(raw, "w")
>          file.write("".join(html).encode('utf-8'))

You can't encode byte data, it's already encoded. So you're forcing the 
Python system to implicitly decode it (using ASCII codec) before letting 
you encode it to utf-8.  If you think it's already in utf-8, then omit 
the encode() call there.

Additionally, you can debug things with some simple print statements, at 
least if you decompose your 3-function line so you can get at the 
intermediate data.  Split the line into three parts;
     temp1 = "".join(html)     #temp1 is byte data
     temp2 = temp1.decode()    #temp2 is unicode data
     temp3 = temp2.encode("utf-8")  #temp3 is byte data again
     file.write(temp3)

Now, you'll presumably get the error on the second line, so examine the 
bytes around byte 783.  Make sure it's really in utf-8, and if it is, 
then skip the decode and the encode.  If it's not, then Andrew's advice 
is pertinent.

I would also look at the variable html.  It's a list, but what are the 
types of the elements in it?

>          file.close()
>
> The variable html is a list containing the lines of HTML to write to the
> file.  It fails when it contains accented characters (an é in this
> case).  Here's the traceback:-
>
> Traceback (most recent call last):
>    File "/usr/local/lib/python2.7/dist-packages/gallery/galleries.py", line 41, in run self._recurse()
>    File "/usr/local/lib/python2.7/dist-packages/gallery/galleries.py", line 272, in _recurse os.path.walk(self.props["sourcedir"], self.processDir, None)
>    File "/usr/lib/python2.7/posixpath.py", line 246, in walk walk(name, func, arg) File "/usr/lib/python2.7/posixpath.py", line 246, in walk walk(name, func, arg)
>    File "/usr/lib/python2.7/posixpath.py", line 246, in walk walk(name, func, arg) File "/usr/lib/python2.7/posixpath.py", line 238, in walk func(arg, top, names)
>    File "/usr/local/lib/python2.7/dist-packages/gallery/galleries.py", line 263, in processDir self.createGallery()
>    File "/usr/local/lib/python2.7/dist-packages/gallery/galleries.py", line 215, in createGallery self.picturemanager.createPictureHTMLs(self.footer)
>    File "/usr/local/lib/python2.7/dist-packages/gallery/picturemanager.py", line 84, in createPictureHTMLs curPic.createPictureHTML(self.galleryDirectory, self.getStylesheet(), self.fullsize, footer)
>    File "/usr/local/lib/python2.7/dist-packages/gallery/picture.py", line 361, in createPictureHTML file.write("".join(html).encode('utf-8')) UnicodeDecodeError: 'ascii' codec can't decode byte 0xc3 in position 783: ordinal not in range(128)
>
>
>
> If I understand correctly the encode() is saying that it can't
> understand the data in the html because there's a character 0xc3 in it.
> I *think* this means that the é is encoded in UTF-8 already in the
> incoming data stream (should be as my system is wholly UTF-8 as far as I
> know and I created the directory name).
>
> So how do I change the code so I don't get the error?  Do I just
> decode() the data first and then encode() it?
>


-- 
DaveA



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