Question: I want to remove every 3rd item from list.
For Example:

```
list1 = list(['a','b','c','d','e','f','g','h','i','j'])

```

After removing indexes which are multiple of three the list will be:

```
['a','b','d','e','g','h','j']

```

How can I achieve this?

Answer: 
You may use `enumerate()`:

```
>>> x = ['a','b','c','d','e','f','g','h','i','j']
>>> [i for j, i in enumerate(x) if (j+1)%3]
['a', 'b', 'd', 'e', 'g', 'h', 'j']

```

*Alternatively*, you may create the copy of list and delete the values at interval. For example:

```
>>> y = list(x) # where x is the list mentioned in above example
>>> del y[2::3] # y[2::3] = ['c', 'f', 'i']
>>> y
['a', 'b', 'd', 'e', 'g', 'h', 'j']

```
```
[v for i, v in enumerate(list1) if (i + 1) % 3 != 0]

```

It seems like you want the third item in the list, which is actually at index 2, gone. This is what the `+1` is for.