UnicodeDecodeError in IPython Notebook caused by negative numbers in plt.legend()

[goulu]

Encountered a strange error shown in a small IPython Notebook here : https://gist.github.com/goulu/ba518d1a0a5267c0d3f3

in the method repr_svg method that generates a svg plot for IPython Notebook ( 2.7 kernel )

plt.legend()
savefig(output, format='svg')

generates content like

<!-- \xe2\x88\x925 --> 

for "-5" in the legend, which causes a UnicodeDecodeError in JSON via Jupyter client

[jenshnielsen]

The svg output contains unicode characters so that can't we written to a bytesIO object which cannot handle svg files. Is there any reason that you cannot use a StringIO object which handles unicode objects

[goulu]

I used BytesIO because the same rendering method also generates png, but I'll definitely have a look at StringIO, thanks.

In the meantime I solved my problem by adding a .decode('utf-8') at the end of the repr_svg method. Sorry for the noise ...