A leading space is missing in the output of
mpl.text(1, 1, '% .3f' % 1.234)
if used within the TeX backend. Whereas it is not
missing in the plain non-TeX backend.
Here is an example:
import pylab as mpl
#mpl.rcParams['text.usetex'] = False
mpl.rcParams['text.usetex'] = True
mpl.plot([1,3,2])
mpl.text(1, 2.0, '% .3f' % 1.234)
mpl.text(1, 1.9, '% .3f' % -1.234)
mpl.show()
Ciao
Andreas