I'd recommend using just the boolean check on `orders` instead of calling `len()` on each order, since just using the boolean check is at least twice at fast.

```
In [1]: foo = list()

In [2]: %timeit if len(foo) > 0: return 1
10000000 loops, best of 3: 54.5 ns per loop

In [3]: %timeit if foo: return 1
10000000 loops, best of 3: 23 ns per loop
```