title: Replace Nulls of Struct type column using Pyspark
body: <p>I have a use case where I want to replace nulls in <strong>StructType</strong> columns with empty values.
  Below is sample which you can use to recreate the scenario:</p>
  <pre class="lang-py prettyprint-override"><code>from pyspark.sql.types import StructType, StructField, StringType, IntegerType
  
  data = [(1, [1, &quot;Aman&quot;]), (2, [2, &quot;Raman&quot;]), (3, [3, &quot;Baman&quot;]), (4, None)]
  
  schema = StructType(
      [
          StructField(&quot;ID&quot;, IntegerType(), True),
          StructField(
              &quot;Name&quot;,
              StructType(
                  [
                      StructField(&quot;NameID&quot;, IntegerType(), True),
                      StructField(&quot;FirstName&quot;, StringType(), True),
                  ]
              ),
              True,
          ),
      ]
  )
  
  df = spark.createDataFrame(data, schema)
  
  df.show()
  </code></pre>
  <p>I want to know how we can replace nulls in <code>Name</code> column.</p>