title: Count number of capital letters in file Python?
body: <p>I am trying to count the number of unique capital letter from a text file which contains text data. I have done with counting the capital letter from file but need your help in how to count unique capital letters.</p>
  
  <p>This is what i have tried yet:</p>
  
  <pre><code>with open('demo.txt') as countletter:
      count = 0
      text = countletter.read()
      for character in text:
          if character.isupper():
              count += 1
  print(count) 
  </code></pre>