Sorted will iterate through the iterable it's passed. If it already has a count for a given character, get. The sample code in your question is clearly trying to count the number of occurrences of each character:
Evo X Timing Chain Code at Noah Bugnion blog
As advised by andy e while answering this question, it's not good for your script's performance if it's repeatedly building. If so, how should i then do it? 11 here is my solution.
The get/set pattern provides a structure that allows logic to be added during the setting ('set') or retrieval ('get') of a property instance of an instantiated.
As you have found, get just gets the value corresponding to a given key.
