title: Panda's Update information based on bins / cutting
body: <p>I'm working on a dataset which has a large amount of missing information.
  I understand I could use FillNA but i'd like to base my updates on the binned values of another column.</p>
  
  <p>Selection of missing data:</p>
  
  <pre><code>missing = train[train['field'].isnull()]
  </code></pre>
  
  <p>Bin the data (this works correctly):</p>
  
  <pre><code>filter_values = [0, 42, 63, 96, 118, 160]
  labels = [1,2,3,4,5]
  out = pd.cut(missing['field2'], bins = filter_values, labels=labels)
  counts = pd.value_counts(out)
  print(counts)
  </code></pre>
  
  <p>Now, based on the bin assignments,  I would like to set the correct bin label, to the <code>missing/train['field']</code> for all data assigned to this bin.</p>