title: 'where' in apache spark
body: <pre><code>df:
  
  -----------+
  |       word|
  +-----------+
  |       1609|
  |           |
  |        the|
  |    sonnets|
  |           |
  |         by|
  |    william|
  |shakespeare|
  |           |
  |         fg|
  </code></pre>
  
  <p>This is my data frame. How to remove the empty rows (to remove the rows that contain '') using the 'where' clause. </p>
  
  <pre><code>code:
  
  df.where(trim(df.word) == "").show()
  
  output:
  
  ----+
  |word|
  +----+
  |    |
  |    |
  |    |
  |    |
  |    |
  |    |
  |    |
  |    |
  |    |
  </code></pre>
  
  <p>Any help is appreciated.</p>