weird result trying to remove numbers from a list

[boring_accountant]

You are modifying a list that you are looping through. Here's an idea of what is happening:

• Start at position 0 with value 1
  
• Remove element at position 0, all following elements are shifted back by one
  
• Continue at position 1 with value 3 (you skipped over 2)
  
• Remove element at position 1, all following elements...
  
• Continue at position 2 with value 5 (you skipped over 4)
  
• Remove element at position 2, ...
  
• All following elements are preserved because they do not meet the if test.
  

One solution is to create an empty list and append to it all elements that you would not remove from the original list:

both = nums + words
new_list = []

for each in both:
    if each not in range(1000):
        new_list.append(each)

I haven't tested this but it should do the trick.