title: How to split tuple of tuples into columns
body: <p>I have a pandas dataframe where one column is a tuple with a nested tuple. The nested tuple has two existing ids. I want to explode every element in the total tuple into new appended columns. Here's my df so far:</p>
  
  <pre><code>df
    id1  id2   tuple_of_tuple
  0 a    e    ('cat',100,('a','f'))
  1 b    f    ('dog',100,('b','g'))
  2 c    g    ('cow',100,('d','h'))
  3 d    h    ('tree',100,('c','e'))
  </code></pre>
  
  <p>I was trying to implement the code below on a small subset of data, and it seemed to work. There were new appended columns with each extracted/exploded element where it needed to be.</p>
  
  <pre><code>df[['Link_1', 'Link_2','Link_3','Link_4']] = df['tuple_of_tuple'].apply(pd.Series)
  </code></pre>
  
  <p>But when I apply it on the entire dataset, I get the error "ValueError: Columns must be same length as key". (I should mention that there are a couple NaN's littered around, as in an entire entry in the row for the tuple_of_tuple column will just be NaN). How can I fix this?</p>