title: Remove duplicate elements from list when there are many duplicate elements are present
body: <p>I'm trying to remove a duplicate element from a list, it is not able to remove it ("1"), can somebody explain what I'm doing wrong </p>
  
  <pre><code>lst=[1,2,3,4,1,1,1,5,6,7,1,2]
      for i in lst:
          print(i)
          if i==1:
             lst.remove(i)
  </code></pre>
  
  <p>expected output - </p>
  
  <pre><code>[2,3,4,5,6,7,2]
  </code></pre>
  
  <p>actual output -</p>
  
  <pre><code>[2,3,4,5,6,7,1,2]
  </code></pre>