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# Finding the index of an element in a list in Python

schedule Aug 12, 2023
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We can find the index of an element in a list in Python using either the `index(~)` method or the `enumerate(~)` method.

Method

When to use

`index(~)`

If the list does not contain duplicate items

`enumerate(~)`

If the list contains duplicate items

# Examples

## index method

If there are no duplicate elements in the list we can use the `index(~)` method:

``` l = ['a', 'b', 'c', 'd']print(l.index('b')) 1 ```

The `index(~)` method only returns the position of the first occurrence of an element, hence caution is required if your list contains duplicate items.

If the element does not exist in the list we get a `ValueError`:

``` print(l.index('e')) ValueError: 'e' is not in list ```

## enumerate method

If there are duplicate elements in the list, we can use the `enumerate(~)` method:

``` dupe_l = ['a', 'b', 'c', 'd', 'a', 'b']print([i for i, x in enumerate(dupe_l) if x == 'b']) [1, 5] ```

If the element does not exist in the list we return an empty list:

``` print([i for i, x in enumerate(dupe_l) if x == 'e']) [] ```
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