title: Map a list of strs to list of ints
body: <p>In Python, I want to convert strings that are ints in a list to integers.</p>
  <p>If I have <code>a = ['1', 'ABC', '2', 'XYZ']</code>, then I'd like to make <code>[1, 'ABC', 2, 'XYZ']</code>. What will be a good Pythonic way of doing this?</p>
  <p>I tried <code>a = list(map(int, a))</code>. However, this works only if each element is int already. E.g. <code>'1'</code>, <code>'2'</code>, <code>'100'</code>, etc.</p>