title: Describe a Dataframe on PySpark
body: <p>I have a fairly large Parquet file which I am loading using</p>
  
  <pre><code>file = spark.read.parquet('hdfs/directory/test.parquet')
  </code></pre>
  
  <p>Now I want to get some statistics (similar to pandas <code>describe()</code> function). What I've tried to do was:</p>
  
  <pre><code>file_pd = file.toPandas()
  file_pd.describe()
  </code></pre>
  
  <p>but obviously this requires to load all the data in memory and it will fail. 
  Can anyone suggest a workaround? </p>