When I call pyplot.title(\'some string\') it throws the exception, \'str\' object is not callable\'. I copied the following from the matplotlib onl
pyplot.title(\'some string\')
\'str\' object is not callable\'
It happened to me because I tried to do plot.title = "Some string" so that rewrote the title() method. That's the exact reason why it happens :) . As others have said you just need to restart the kernel, no need to reinstall.
plot.title = "Some string"
title()