Python elegant assignment based on True/False values

Question

I have a variable I want to set depending on the values in three booleans. The most straight-forward way is an if statement followed by a series of elifs:

if a a         


        

Answer 1

You can think of a, b, and c as three bits that when put together form a number between 0 and 7. Then, you can have an array of the values ['first', 'second', ... 'eighth'] and use the bit value as an offset into the array. This would just be two lines of code (one to assemble the bits into a value from 0-7, and one to lookup the value in the array).

Here's the code:

nth = ['eighth', 'seventh', 'sixth', 'fifth', 'fourth', 'third', 'second', 'first']
nth[(a and 4 or 0) | (b and 2 or 0) | (c and 1 or 0)]