Increase speed/performance by roughly 10%

[bandjhughes]

use list comprehension
DRY refactor
Use enumerate
Reverse order in if statement to avoid math when possible
Remove unnecessary assignment
Remove unnecessary cast (when more efficient)
Remove unnecessary elif statement
Remove unnecessary variables passed to functions

[bandjhughes]

No changes to functionality (at least not intentionally), just minor changes to improve runtime speed. Before changes were made, the random seed was set, and a (repeatable) confusion matrix was generated for a multi-class classifier as a baseline.

After the changes, the exact same confusion matrix is still produced, and the average runtime is reduced around 9-10 percent.