All you need to know, and just use comparison operators for fastest efficiency:
https://sciencing.com/rules-length-triangle-sides-8606207.html

Clever using pythons and style.

This is best practice for production code (programming at a job).

For Python, either import collections, Counter or a simple dict comprehension for more info:
https://docs.python.org/3/tutorial/datastructures.html?highlight=dict%20comprehensions

Most concise and clear solution