how to draw dendrogram in python
>>> hierarchy.set_link_color_palette(['m', 'c', 'y', 'k'])
>>> fig, axes = plt.subplots(1, 2, figsize=(8, 3))
>>> dn1 = hierarchy.dendrogram(Z, ax=axes[0], above_threshold_color='y',
... orientation='top')
>>> dn2 = hierarchy.dendrogram(Z, ax=axes[1],
... above_threshold_color='#bcbddc',
... orientation='right')
>>> hierarchy.set_link_color_palette(None) # reset to default after use
>>> plt.show()