title: Subtract String List Elements from 2 lists
body: <p>I have the following code, which works fine for adding string elements from 2 lists:</p>
  <pre><code>list_1 = ['2 Red', '8 Blue', '4 Green']
  list_2 = ['10 Red', '2 Blue', '3 Green']
  
  list_1.extend(list_2)
  
  results = {}
  
  for elem in list_1:
      number, color = elem.split()
      results[color] = results.get(color, 0) + int(number)
  
  result = [f&quot;{i} {p}&quot; for i, p in zip(results.values(), results.keys())]
  
  Output: ['12 Red', '10 Blue', '7 Green']
  </code></pre>
  <p>Now, I want to do basic subtraction for the same elements, that the output is as follows:</p>
  <pre><code>Output: ['8 Red', '6 Blue', '1 Green']
  </code></pre>
  <p>I thought I understood my code, but obviously  I don't, I get stuck with the + operator for int(numbers) &amp; I do not understand the zip() function. I hope you guys can help me.</p>
  <p>Stay healthy and have a nice day!</p>