import matplotlib.pyplot as plt
import numpy as np

plt(np.arange(10))     #NameError: name 'plot' is not defined
plt.show()

fig = plt.figure()

ax1 = fig.add_subplot(2, 2, 1)

ax2 = fig.add_subplot(2, 2, 2)

ax3 = fig.add_subplot(2, 2, 3)

fig.show()

from numpy.random import randn

plt.plot(randn(50).cumsum(), 'k--')     #AttributeError: 'Figure' object has no attribute 'plot'