pygal rendering png/svg black pictures

Just in case anyone else encounters something similar, my problem was that the SVG looked fine in a browser, but no in Inkscape. I was using custom css, and setting fill: transparent on some elements. It should be fill: none.

You need to install lxml as well. So assuming you are in a virtualenv run the following command on your bash/zsh prompt:

pip install lxml

If you only have the other 3 libraries, i.e. cssselect, pycairo, tinycss. Then you will be able to properly render an SVG but the PNG render function will produce a solid black image file (without lxml installed)

The gist below shows all the steps:

[FIRST: install the required libraries]

• pip install lxml
• pip install cairosvg
• pip install tinycss
• pip install cssselect

[SECOND: create the file]

"""
pygal_render_png
""""
import pygal

bar_chart = pygal.Bar()
bar_chart.add('Fibonacci', [0, 1, 1, 2, 3, 5, 8, 13, 21, 34, 55])
bar_chart.render_to_file('bar_chart.svg')
bar_chart.render_to_png(filename='bar_chart.png')

If you get black svg images in Image Viewer (Ubuntu) or Gimp, try opening the image in Chrome.