title: How to remove commas from ALL the column in pandas at once
body: <p>I have a data frame where all the columns are supposed to be numbers. While reading it, some of them were read with commas.  I know a single column can be fixed by</p>
  <pre class="lang-py prettyprint-override"><code>df['x']=df['x'].str.replace(',','')
  </code></pre>
  <p>However, this works only for series objects and not for entire data frame. Is there an elegant way to apply it to entire data frame since every single entry in the data frame should be a number.</p>
  <p>P.S: To ensure I can <code>str.replace</code>, I have first converted the data frame to str by using</p>
  <pre class="lang-py prettyprint-override"><code>df.astype('str')
  </code></pre>
  <p>So I understand, I will have to convert them all to numeric once the comma is removed.</p>