title: Pie Chart Creation issue
body: <p>I'm sure I'm being a complete numpty here.  I'm trying to create a couple of pie charts, showing the demographics of respondents to a survey (in this case, Parents or Teachers).  Obviously, at the moment, the columns contain strings, which can't be put into a pie chart.  So I thought I'd do a count of the strings and put that into a variable.  However, when I try to then use that in pie chart, it's failing.</p>
  <p>I know this is probably something really simple, and I have Googled around, but I can't seem to find a way to get this working.</p>
  <p>Code as follows:</p>
  <pre><code>respondents_pie=df.groupby('Respondents').size()
  
  print(respondents_pie)
  </code></pre>
  <p>Output</p>
  <p>Respondents
  Parents     31
  Teachers    20
  dtype: int64</p>
  <pre><code>fig=plt.figure()
  ax=fig.add_axes(0,0,1,1)
  ax.axis('equal')
  ax.pie(respondents_pie, autopct='%1.2f%%')
  plt.show()
  </code></pre>
  <p>Error is:  TypeError: from_bounds() argument after * must be an iterable, not int
  Error is on line 2 of the code (<code>ax=fig.add_axes(0,0,1,1)</code>)
  How have I messed this one up?</p>