python3, matlibplot, gui, ValueError could not convert string to float
Traceback (most recent call last):
File "./ex1.py", line 15, in module
ax.bar(labels, a_means, width , yerr = a_std , label = 'A')
File "/usr/lib/python2.7/dist-packages/matplotlib/__init__.py", line 1814, in inner
return func(ax, *args, **kwargs)
File "/usr/lib/python2.7/dist-packages/matplotlib/axes/_axes.py", line 2129, in bar
label='_nolegend_'
File "/usr/lib/python2.7/dist-packages/matplotlib/patches.py", line 641, in __init__
self._x = float(xy[0])
ValueError: could not convert string to float: G1
