title: python dask dataframe splitting column of tuples into two columns
body: <p>I am using python 2.7 with dask </p>
  
  <p>I have a dataframe with one column of tuples that I created like this:</p>
  
  <pre><code>table[col] = table.apply(lambda x: (x[col1],x[col2]), axis = 1, meta = pd.Dataframe) 
  </code></pre>
  
  <p>I want to re convert this tuple column into two seperate columns 
  In pandas I would do it like this:</p>
  
  <pre><code>table[[col1,col2]] = table[col].apply(pd.Series) 
  </code></pre>
  
  <p>The point of doing so, is that dask dataframe does not support multi index and i want to use groupby according to multiple columns, and wish to create a column of tuples that will give me a single index containing all the values I need (please ignore efficiency vs multi index, for there is not yet a full support for this is dask dataframe) </p>
  
  <p>When i try to unpack the tuple columns with dask using this code: </p>
  
  <pre><code>rxTable[["a","b"]] = rxTable["tup"].apply(lambda x: s(x), meta = pd.DataFrame, axis = 1)
  </code></pre>
  
  <p>I get this error </p>
  
  <blockquote>
    <p>AttributeError: 'Series' object has no attribute 'columns'</p>
  </blockquote>
  
  <p>when I try</p>
  
  <pre><code>rxTable[["a","b"]] = rxTable["tup"].apply(dd.Series, axis = 1, meta = pd.DataFrame)
  </code></pre>
  
  <p>I get the same </p>
  
  <p>How can i take a column of tuples and convert it to two columns like I do in Pandas with no problem?</p>
  
  <p>Thanks</p>