# Traversing Data

Follow step-by-step instructions to calculate the distance between all locations with OpenStreetMap.

## We'll cover the following

We calculated the distances between two places. However, we need to calculate the distances between all locations to be able to calculate the shortest total distance. Since we don’t want to repeat the previous step manually for all locations, we’ll solve it via a loop instead.

## Distance between all locations

To get started, let’s first calculate the distance between three stores: A, B, and C. With `islice`

, we iterate over the `df.iterrows()`

iterable, which starts at `counterFixed`

. Using `df.index`

`!= i`

, we ensure that the distance from any store to itself is not calculated.

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