python：The word in List can't be removed : [As you can see ,i'm trying to delete the word in a list whose length is 1 or 2 ,but "P" and "ye" can't be find and removed!][1]


[the result of mine][2]


  [1]: http://i.stack.imgur.com/7kkKL.png
  [2]: http://i.stack.imgur.com/0EEIe.png