rst2pdf : Generate pdf with formulas

Question

I need to generate a report with formulas. I found the library rst2pdf. I like to work with the library, but there was a problem when generating pdf with formulas. To generate a formula I use math role. The following code does not work. The error occurs in the module PIL. How to fix it.

#!/usr/bin/env python
# -*- coding: utf-8 -*-

from rst2pdf.createpdf import RstToPdf

mytext = u"""
================
Name of document
================

Title
---------

====================  ==========  ==========
Header row, column 1  Header 2    Header 3
====================  ==========  ==========
body row 1, column 1  column 2    column 3
body row 2, column 1  column 2    column 3
body row 3, column 1  column 2    column 3
====================  ==========  ==========

:math:`\\frac{1}{\\sigma\\sqrt{2\\pi}}\\exp\\left(-\\frac{(x-\\mu)^2}{2\\sigma^2}\\right) = 123`

"""

pdf = RstToPdf()
pdf.createPdf(text = mytext, output='foo.pdf')

Output of the script

File "C:\Python27\lib\site-packages\PIL\Image.py", line 1549, in save
    raise KeyError(ext) # unknown extension
KeyError: '.png'

Answer 1

This error happens when PIL/Pillow does not recognise the file extension chosen to save with.

from PIL import Image
im = Image.new("RGB", (100, 100))
im.save("test", ".png")

gives

Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "lib/python3.7/site-packages/PIL/Image.py", line 1939, in save
     save_handler = SAVE[format.upper()]
KeyError: '.PNG'

This is because ".png" is not a valid format, "png" is. What you need to do is

im.save("test", "png")

or

im.save("test.png")