Re: [Rdkit-discuss] Export pandas DataFrame to xlsx with molecule images

[Grégori G. <gr...@ge...>]

Hi Samo,

I used a few years ago the PHPExcel library to put images into an Excel 
file, and it was not necessary to use physical files.
Having a quick look at the library I found this class (probably the one 
I used): PHPExcel_Worksheet_MemoryDrawing (source code: 
https://github.com/clariondoor/PHPExcel/blob/master/Worksheet/MemoryDrawing.php)
The interesting bit:
     public function __construct()
     {
         // Initialise values
         $this->_imageResource        = null;
         $this->_renderingFunction     = self::RENDERING_DEFAULT;
         $this->_mimeType            = self::MIMETYPE_DEFAULT;
         $this->_uniqueName            = md5(rand(0, 9999). time() . 
rand(0, 9999));

         // Initialize parent
         parent::__construct();
     }

Thus I'm pretty sure you can use the same trick in python XlsxWriter 
(have a look at the _add_image_files function in packager.py), using a 
random file name and a bit stream to the image, as described here: 
http://xlsxwriter.readthedocs.org/en/latest/example_images_bytesio.html#ex-images-bytesio:

filename   = 'python.png'
image_file = open(filename, 'rb')
image_data = BytesIO(image_file.read())
image_file.close()
# Write the byte stream image to a cell. The filename must  be specified.
worksheet.insert_image('B8', filename, {'image_data': image_data})

At least it's worth a try!
Another trick I had to do both with PHPExcel and in VBA was to set the 
width of columns three times to make sure that it was actually correct. 
Don't ask me why... Just in case you face some width issues.

Good luck!

Grégori


On 30. 10. 14 16:49, Samo Turk wrote:
> Hi rdkiters,
>
> Due to popular demand I started to work on a function to export pandas 
> DataFrame to xlsx with molecule images embedded.
> Because of the xlsx specifics the code is not optimal. The most 
> annoying thing about this implementation is that it has to write all 
> images to the hard drive, before it packs them in xlsx (and deletes 
> them at the end). I checked two python xlsx libraries and both save 
> images that way. If someone finds better solution, please share it.
>
> The dimensions of cells with images are not optimal because Excel is 
> weird. :) From xlsxwriter docs): "The width corresponds to the column 
> width value that is specified in Excel. It is approximately equal to 
> the length of a string in the default font of Calibri 11. 
> Unfortunately, there is no way to specify “AutoFit” for a column in 
> the Excel file format."
>
> It crashes if value of a cell is of wrong type so use 
> df['value'].astype() to fix incorrectly assigned types.
>
> Resulting files work nicely in Office 365 (standalone and web app), 
> but for some reason don't work optimally with LibreOffice (after row 
> ~125 it stacks all images).
>
> I made a pull request on GitHub: https://github.com/rdkit/rdkit/pull/371
> Demo: 
> http://nbviewer.ipython.org/github/Team-SKI/snippets/blob/master/IPython/rdkit_hackaton/XLSX%20export.ipynb
> Demo xlsx file: 
> https://github.com/Team-SKI/snippets/blob/master/IPython/rdkit_hackaton/demo.xlsx
>
> Regards,
> Samo
>
>
> ------------------------------------------------------------------------------
>
>
> _______________________________________________
> Rdkit-discuss mailing list
> Rdk...@li...
> https://lists.sourceforge.net/lists/listinfo/rdkit-discuss