title: Why am I getting different values for len(bins) and numb_bins when using matplotlib histogram module?
body: <p>I've generated a histogram using data from a file. Yet when I print the len(bins) it is different to the number of bins?</p>
  
  <pre><code>with open ('EHSS.dat') as f:
          data = [line.rstrip() for line in f]
  
  x = [ float(i) for i in data]
  
  num_bins = 7
  
  plt.figure(0)
  n, bins, patches = plt.hist(x, num_bins, facecolor='purple', alpha=0.5)
  plt.savefig('fig0.png')
  
  print(len(bins), num_bins)
  </code></pre>
  
  <p>This code gives len(bins) = 8 while num_bins = 7, why is this?</p>