Practical Programming, 2nd Edition

Using Local Variables for Temporary Storage

Some computations are complex, and breaking them down into separate steps can lead to clearer code. Here, we break down the evaluation of the quadratic polynomial ax²+ bx + c into several steps (notice that all the statements inside the function are indented the same amount of spaces in order to be aligned with each other):

>>> def quadratic(a, b, c, x):
...     first = a * x ** 2
...     second = b * x
...     third = c
...     return first + second + third
...
>>> quadratic(2, 3, 4, 0.5)
6.0
>>> quadratic(2, 3, 4, 1.5)
13.0

Variables like first, second ...