title: Replacing string element in for loop Python
body: <p>I am reading data in from a text file so each row is a list of strings, and all those lists are in a data list. So my lists look like:</p>
  
  <pre><code>data = [row1, row2, etc.]
  row1 = [str1, str2, etc.]
  </code></pre>
  
  <p>I am trying to remove any $ or % signs that appear in the strings in a row list. I have checked that if I try and do this for one individual element, say the second row and the fourth element has a "%", so:</p>
  
  <pre><code>data[1][3] = data[1][3].replace("%","")
  </code></pre>
  
  <p>This will properly remove it, but when I try and use a nested for loop to do it all:</p>
  
  <pre><code>for row in data:
      for x in row:
          x = x.replace("%","")
          x = x.replace("$","")
  </code></pre>
  
  <p>This doesn't remove any of the % or $ signs, I have tried just doing it without the second replace to see if it would at least remove the % signs, but even that didn't work.</p>
  
  <p>Any ideas why this wouldn't work, or how I could do this?<br>
  Thanks in advance for any help!</p>