Why does my code not return an error but still doesn't create a window?

Question

When I run this code it doesn't return error but doesn't create a window. Somebody please help.

import pygal as pyg

line_chart = pyg.HorizontalBar()
line_chart.title = 'Friends favorite pizza topping'
line_chart.add('olives', 24)
line_chart.add('TOMATO', 32)
line_chart.add('pepperoni', 42)
line_chart.add('mushroom', 0.5)
line_chart.add('other', 1.5)
line_chart.render()

Answer 1

It generates SVG data which you can assign to variable

 data = line_chart.render()

and use to embed in HTML or to save in file

 with open('image.svg', 'wb') as fh:  # need binary mode
     fh.write(data)

or

 line_chart.render_to_file('image.svg')

 line_chart.render_to_png('image.png')

and later you can open it in browser or viewer.

If you want to see it at once in web browser then you need

 line_chart.render_in_browser()

There are other render_.... to generate response for Flask and Django, etc.

---

Maybe if you use render() in jupyter notebook or Google Colab (which run in web browser) then it will display it at once.

---

import pygal as pyg

line_chart = pyg.HorizontalBar()
line_chart.title = 'Friends favorite pizza topping'
line_chart.add('olives', 24)
line_chart.add('TOMATO', 32)
line_chart.add('pepperoni', 42)
line_chart.add('mushroom', 0.5)
line_chart.add('other', 1.5)

data = line_chart.render(pretty_print=True)
print(data.decode())

with open('image.svg' 'wb') as fh:
    fh.write(data)
    
#line_chart.render_to_file('image.svg')
#line_chart.render_to_png('test.png')

line_chart.render_in browser()