title: plot a histogram over specific columns of a dataframe pandas
body: <p>I have a dataframe with a cloumn called rel_positive, and a column called len_text_celaned
  I want to plot a histogramm where rel_positive is displayed as a function of len_text_celaned.</p>
  
  <p>I tried it with this straightforward approach:</p>
  
  <pre><code>df_rel.rel_positive.hist(df_rel.len_text_celaned)
  </code></pre>
  
  <p>As far as I understand the first argument in the brackets of df.hist is the x-values?
  but it returns me an array rather than a plot.</p>
  
  <pre><code>array([[&lt;matplotlib.axes._subplots.AxesSubplot object at 0x0000020AF0104630&gt;,
          &lt;matplotlib.axes._subplots.AxesSubplot object at 0x0000020AF48A4EF0&gt;,
  </code></pre>
  
  <p>Maybe I'm overseeing a very stupid mistake, or is there another way?</p>
  
  <p>EDIT:
  Apparently it looks like the array contains several lists.</p>