from matplotlib import pyplot as plt

drinks = ["cappuccino", "latte", "chai", "americano", "mocha", "espresso"]
ounces_of_milk = [6, 9, 4, 0, 9, 0]
error = [0.6, 0.9, 0.4, 0, 0.9, 0]

#Yerr -> element at i position represents +/- error[i] variance on bar[i] value
plt.bar( range(len(drinks)),ounces_of_milk, yerr=error, capsize=15)
plt.show()
[((9, 0, 9, 10), 'matplotlib.pyplot.show', 'plt.show', ({}, {}), '()', True, 'from matplotlib import pyplot as plt\n')]