I have a list of tuples (always pairs) like this:

```
[(0, 1), (2, 3), (5, 7), (2, 1)]

```

I'd like to find the sum of the first items in each pair, i.e.:

```
0 + 2 + 5 + 2

```

How can I do this in Python? At the moment I'm iterating through the list: 

```
sum = 0
for pair in list_of_pairs:
   sum += pair[0]

```

I have a feeling there must be a more Pythonic way.