and get the following output in the console:
Saving 8.96 x 5.56 in image
Saving 8.96 x 5.56 in image
Saving 8.96 x 5.56 in image
Saving 8.96 x 5.56 in image
This is due to the special characters in the titles, that are not accepted in filenames. It seems to work if I use this title2 as filename: title2 = str_replace(graph_title, " : ", "_") (on Windows 10; it could be system-dependent).