title: Convert List into dataframe spark scala
body: <p>I have a list with more than 30 strings. how to convert list into dataframe .
  what i tried:</p>
  
  <p>eg</p>
  
  <pre><code>Val list=List("a","b","v","b").toDS().toDF()
  
  Output :
  
  
  +-------+
  |  value|
  +-------+
  |a      |
  |b      |
  |v      |
  |b      |
  +-------+
  
  
  Expected Output is 
  
  
    +---+---+---+---+
  | _1| _2| _3| _4|
  +---+---+---+---+
  |  a|  b|  v|  a|
  +---+---+---+---+
  </code></pre>
  
  <p>any help on this .</p>