Work along three paths

A diatomic gas goes from A ($1.5\ \text{L}$, $3.8 \times 10^{5}\ \text{Pa}$) to B ($4.5\ \text{L}$, $1.3 \times 10^{5}\ \text{Pa}$) along three different paths. You will make the program find the work along each path from the area under it, the change of internal energy, and the heat each path needs.

The idea. Along a straight piece the work is the average pressure times $\Delta V$; a path's work is the sum over its pieces. For a diatomic ideal gas $U = \tfrac52 pV$, so $\Delta U$ is the same for every path. Then $Q = \Delta U + W$.

Your tasks.

1. Finish work(path): add up the work of each straight piece of the path.
2. Work out dU, the change of internal energy from A to B.
3. Work out the heat Q for each path.