Python histogram outline
It looks like either your linewidth was set to zero or your edgecolor was set to 'none'. Matplotlib changed the defaults for these in 2.0. Try using:
plt.hist(gaussian_numbers, edgecolor='black', linewidth=1.2)
It looks like either your linewidth was set to zero or your edgecolor was set to 'none'. Matplotlib changed the defaults for these in 2.0. Try using:
plt.hist(gaussian_numbers, edgecolor='black', linewidth=1.2)