title: How to loop vertically through a list in Python?
body: <p>This is my code atm:</p>
  <pre><code>puzzle = [
  ['1','1','1','1','1','1','1','1','1','1'],
  ['1','0','0','0','0','1','1','1','1','1'],
  ['1','1','0','1','0','0','0','0','0','0'],
  ['0','1','0','0','0','0','0','0','0','0'],
  ['0','0','1','0','1','0','1','0','0','0'],
  ['0','0','0','0','1','0','0','0','0','0'],
  ['1','0','0','0','1','0','1','0','1','0'],
  ['0','0','0','0','1','0','0','0','0','1'],
  ]
  
  #30 1 s
  
  counter1 = 0
  counter2 = 0
  
  for a in puzzle:
     b = ''.join(a)
     for search in b:
         if search == '1':
             counter1 = counter1 + 1
         if counter1 &gt; counter2:
             counter2 = counter1
  
  #output should be 3
  print(counter1, counter2)
  </code></pre>
  <p>Now I am trying to loop vertically through my list. So I can find the highest amount of 1's after each other without a 0 interfering. Starting with counting from the top left. Only I haven't the slightest idea on how to do that.
  #output should be 3
  Could someone help me out?</p>