title: Read Text file and Create a Python Dictionary
body: <p>I have a text file as mentioned below:</p>
  
  <pre><code>KEY,NAME,RANK,BOOKNAME,SCORE,AUTHER
  123,ABCD,500,FREEDOM1,15200,PXYZ
  133,EFGH,400,FREEDOM2,15300.5,XTYZ
  nan,SYGH,700,FREEDOM3,15400,RYYZ
  143,LKMN,800,FREEDOM4,15500.5,XYCZ
  </code></pre>
  
  <p>I want read this text file and create a nested dictionary which will be used in my subsequent program.</p>
  
  <pre><code>dict = {
  123:{'NAME':'ABCD','RANK':500,'BOOKNAME':'FREEDOM1', 'SCORE':15200, 'AUTHER':'PXYZ'},
  133:{'NAME':'EFGH','RANK':400,'BOOKNAME':'FREEDOM2', 'SCORE':15300.5, 'AUTHER':'XTYZ'},
  143:{'NAME':'LKMN','RANK':800,'BOOKNAME':'FREEDOM4', 'SCORE':15500.5, 'AUTHER':'XYCZ'}
  }
  </code></pre>
  
  <p>Note: Code should remove the rows with 'nan' KEY values</p>