title: How to convert a list of string numbers into int number in Python3?
body: <p>Possible Duplicate: <a href="https://stackoverflow.com/questions/642154/how-to-convert-strings-into-integers-in-python">How to convert strings into integers in Python?</a></p>
  
  <p>Hello guys, </p>
  
  <p>I am trying to convert this string integers from a nested list to integers. This is my list:</p>
  
  <pre><code>listy = [['+', '1', '0'], ['-', '2', '0']]
  </code></pre>
  
  <p>I trying to convert to this:</p>
  
  <pre><code>[['+', 1, 2], ['-', 2, 0]]
  </code></pre>
  
  <p>This what I have tried so far, but my second line of code is taken from one of the answers in the question <a href="https://stackoverflow.com/questions/642154/how-to-convert-strings-into-integers-in-python">How to convert strings into integers in Python?</a></p>
  
  <pre><code>listy = [['+', '1', '0'], ['-', '2', '0']]
  T2 = [list(map(int, x)) for x in listy]
  print(T2)
  </code></pre>
  
  <p>But it gives me an error:</p>
  
  <pre><code>ValueError: invalid literal for int() with base 10: '+'
  </code></pre>
  
  <p>Is there any possible way to fix this in Python 3?</p>