title: Convert all columns to characters in a data.frame
body: <p>Consider a data.frame with a mix of data types.</p>
  
  <p>For a weird purpose, a user needs to convert all columns to characters.
  How is it best done? A tidyverse attempt at solution is this:</p>
  
  <pre><code>map(mtcars,as.character) %&gt;% map_df(as.list) %&gt;% View()
  c2&lt;-map(mtcars,as.character) %&gt;% map_df(as.list)
  </code></pre>
  
  <p>when I call <code>str(c2)</code> it should say a tibble or data.frame with all characters.</p>
  
  <p>The other option would be some parameter settings for <code>write.csv()</code> or in <code>write_csv()</code> to achieve the same thing in the resulting file output.</p>