title: Read/Write single file in DataBricks
body: <p>I have a file which contains a list of names stored in a simple text file. Each row contains one name. Now I need to pro grammatically append a new name to this file based on a users input.
  For the input itself I use DataBricks widgets - this is working just fine and I have the new name stored in a string object.
  Now I need to append this name to my file.</p>
  
  <p>the file is mounted in the DataBricks File System (DBFS) under /mnt/blob/myNames.txt</p>
  
  <p>when trying to read the file like this:</p>
  
  <pre><code>f = open("/mnt/blob/myNames.txt", "r") 
  print f
  </code></pre>
  
  <p>it returns an error "No such file or directory"</p>
  
  <p>So I tried to wrap my new name into a dataframe and append it to the existing file but this also did not work as dataframe.write.save is designed to write into folders</p>
  
  <p>what would be the most simple python could that I could use to append this new name to my file?</p>