counts = [0, 0, 0, 125, 56, 0, 0, 0, 34, 77, 123, 0, 0, 0]
epsilon = 1e-07
counts = [(x + epsilon) for x in counts]
pylab.bar(align='center', *zip(*enumerate(counts)))
pylab.show()
Force bins with zero-height in matplotlib bar plot