Matplotlib plot is a no-show

Question

When I run this code

import pandas as pd import numpy as np def add_prop(group):     births = group.births.astype(float)     group['prop'] = births/births.sum()     return group  pieces = [] columns = ['name', 'sex', 'births']  for year in range(1880, 2012):     path = 'yob%d.txt' % year     frame = pd.read_csv(path, names = columns)     frame['year'] = year     pieces.append(frame)     names = pd.concat(pieces, ignore_index = True)  total_births = names.pivot_table('births', rows = 'year', cols = 'sex', aggfunc = sum) total_births.plot(title = 'Total Births by sex and year') 

I get no plot. This is from Wes McKinney's book on using Python for data analysis. Can anyone point me in the right direction?

Answer 1

Put

import matplotlib.pyplot as plt 

at the top, and

plt.show() 

at the end.