When using \left and \right in matplotlib with mathtext parsing, it doesn’t recognize useful delimiters. In particular, brace and square bracket are errors:
ylabel(r'$\left\{ \frac{a}{b} \right\}$')
ylabel(r'$\left[ \frac{a}{b} \right]$')
In both cases I get something like
ParseFatalException: Expected a delimiter
$\left\{ \frac{a}{b} \right\}$ (at char 0), (line:1, col:1)
On the other hand \left{ (incorrectly leaving off the backslash) does actually work. I can’t find any way to make the square bracket work, though.
I couldn’t find any bug reports on this, but maybe I’m looking in the wrong place. Any ideas what’s going on?
(matplotlib.__version__ = '1.1.0')
Just to be able to put this question to bed, this was just a bug, and will be fixed in a future release.