Using tuples to collect data

In Chapter 3, Functions, Iterators, and Generators, we showed two common techniques to work with tuples. We've also hinted at a third way to handle complex structures. We can do any of the following techniques, depending on the circumstances:

• Use lambdas (or functions) to select a named item using the index
• Use lambdas (or functions) with the argument to assign a tuple items to parameter names
• Use named tuples to select an item by attribute name or index

Our trip data, introduced in Chapter 4, Working with Collections, has a rather complex structure. The data started as an ordinary time series of position reports. To compute the distances covered, we transposed the data into a sequence of legs with a start position, end position, and distance as a nested three-tuple.

Each item in the sequence of legs looks as follows as a three-tuple:

first_leg = (
    (37.549016, -76.330295), 
    (37.840832, -76.273834), 
    17.7246)

The first two items are the starting and ending...