title: Python String removal covering both uppercase and lowercase
body: <p>trying to make a simple function that'll take a phrase, a letter, and then output the original phrase with that letter removed. I can do the simple version but seem to get my wires crossed when I try to cover both lowercase and uppercase. ( it works fine if i do just 'if i not in aChar)</p>
  
  <p>i.e. If i input 'Board of Trade' and my letter to extract is 'O', i want both the uppercase and the lowercase removed. I'm a beginner so any general tips regarding my code would be much appreciated as well.</p>
  
  <p>Here's my script:</p>
  
  <pre><code>def removal(statement,aChar):
     newstring = ''
     lowercase = aChar.lower()
     uppercase = aChar.upper()
     for i in statement:
         if i not in aChar or lowercase or uppercase:
               newstring = newstring+i
     print(newstring)
  removal('Board of Trade', 'O')    
  </code></pre>