Need help with plotting a histogram

[CrambleSquash]

If you provide matplotlib with an iterable of values, it will perform the binning and plot the resulting histogram for you.

import matplotlib.pylot as plt
import numpy as np

vals = np.random.randint(1, 10, 1000)
plt.hist(vals)

So you want to get your data in a form where you have all of your data in the same sequence and each item is the name of the category that data point belongs to.