title: Dask Groupby Multi-index Level
body: <p>I want to <code>groupby</code> <code>dask</code> multi-index data frame by its <code>level</code>. I want to do the following pandas equivalent in dask:</p>
  <pre><code>df.groupby(level=0)['TARGET']\
                  .apply(lambda x: x.shift().rolling(min_periods=1, window=7).sum()).fillna(0)\
                  .reset_index(name=str(7)+&quot;D&quot;)
  </code></pre>
  <p>The document says that <code>dask</code> doesn't support <code>pandas</code> <code>level</code> argument. How should I tackle this problem in that case?</p>
  <p>I can't use the column name because the column is in the index and the column index which throws the following error:</p>
  <blockquote>
  <p>ValueError: 'CONTACT_ID' is both an index level and a column label, which is ambiguous.</p>
  </blockquote>
  <p>Let me know if you would require data in order to be able to assist. Thanks a lot in advance.</p>