title: How can I display multiple pandas series histograms in the same jupyter notebook cell?
body: <p>I have a dataset with an obvious stratification and I'm looking for graphical evidence that there is a difference in their histograms. Suppose for here that my data set looks something like</p>
  
  <pre><code>id | cat | hour
  ---------------
  1  | a   | 14
  5  | c   | 9
  </code></pre>
  
  <p>If I try and plot each of the histograms for a fixed categorical variable, then I get overlapping graphs. For example, if I write</p>
  
  <pre><code>unique_cats = list(df["cat"].unique())
  for cat in unique_cats:
      df[df["cat"] == cat]["hour"].hist(bins=24, rwidth=0.9,
                                        normed=True, alpha=0.3)
  </code></pre>
  
  <p>then I get a bunch of overlapping histograms. Here's a screenshot:</p>
  
  <p><a href="https://i.stack.imgur.com/jfbtN.png" rel="noreferrer"><img src="https://i.stack.imgur.com/jfbtN.png" alt="overlapping histograms"></a></p>
  
  <p>How can I have my histograms have their own separate line in my jupyter notebook?</p>