In matplotlib you have two main options:
Create your plots and draw them at the end:
import matplotlib.pyplot as plt
plt.plot(x, y)
plt.plot(z, t)
plt.show()
Create your plots and draw them as soon as they are created:
import matplotlib.pyplot as plt
from matplotlib import interactive
interactive(True)
plt.plot(x, y)
raw_input('press return to continue')
plt.plot(z, t)
raw_input('press return to end')