Question

When I run the following code, I get an error:

def genSet(nums):
    for i in range(0, len(nums)-1):
        for x in range(0, len(nums)-1):
            if nums[x] == nums[i]:
                del nums[x] 
    return nums

a = [5, 4, 3, 5, 6, 7, 8, 5, 4, 3]  
print genSet(a)

Output:

Traceback (most recent call last):
  File "49.py", line 9, in <module>
    print genSet(a)
  File "49.py", line 4, in genSet
    if nums[x] == nums[i]:
IndexError: list index out of range

As far as I can tell (I replaced the if statement with “print x, i”) the two for loops are fine, so why is the index out of range?

Answer 1

don’t do del nums[x], since this way you make nums shorter and thus get an exception.

you can simply make a set out of the list by set_nums = set(nums)