title: Explode nested arrays in pyspark
body: <p>I'm looking at the following DataFrame schema (names changed for privacy) in pyspark.</p>
  
  <pre><code>|-- some_data: struct (nullable = true)
  |    |-- some_array: array (nullable = true)
  |    |    |-- element: struct (containsNull = true)
  |    |    |    |-- some_nested_array: array (nullable = true)
  |    |    |    |    |-- element: struct (containsNull = true)
  |    |    |    |    |    |-- some_param_1: long (nullable = true)
  |    |    |    |    |    |-- some_param_2: string (nullable = true)
  |    |    |    |    |    |-- some_param_3: string (nullable = true)
  |    |    |    |-- some_param_4: string (nullable = true)
  |    |    |    |-- some_param_5: string (nullable = true)
  |    |-- some_other_array: array (nullable = true)
  |    |    |-- element: struct (containsNull = true)
  |    |    |    |-- some_param_6: string (nullable = true)
  |    |    |    |-- some_param_7: string (nullable = true)
  |    |-- yet_another_array: array (nullable = true)
  |    |    |-- element: struct (containsNull = true)
  |    |    |    |-- some_param_8: string (nullable = true)
  |    |    |    |-- some_param_9: string (nullable = true)
  </code></pre>
  
  <p>I'm struggling using the explode function on the doubly nested array. I would like ideally to somehow gain access to the paramaters underneath <code>some_array</code> in their own columns so I can compare across some_param_1 through 9 - or even just some_param_1 through 5. </p>