scatter_plot.py

#  Make the matplotlib and matplotlib.pyplot modules available
import matplotlib
matplotlib.use("Agg")
import matplotlib.pyplot as plt

#  Initialize a list for the x values and the y values
x_values = []
y_values = []

done = False

#  Read input from the user until they enter an empty string
while not done:
    pair = raw_input('Enter an x,y pair to be plotted: ')

    #Test to see if the user entered the empty string,  if not
    if pair != '':
        #  Input in the form x,y.  Break this up into an x value and a y value
        values = pair.split(",")
        #  Add the x value to a list of x values
        x_values.append(float(values[0]))
        #  Add the y value to a list of y values
        y_values.append(float(values[1]))
    else:
        done = True

print 'x values are', x_values, 'and y_values are', y_values

#  Create a plot from the lists of x and y values
plt.plot(x_values, y_values)

#  Save the plot into a .png file for later viewing
plt.savefig('scatter.png')