The sample code in your question is clearly trying to count the number of occurrences of each character:
If it already has a count for a given character, get returns it (so it's just incremented by one), else get.
How to get get variables from request in javascript?
Does jquery or yui!
Have this feature built-in?
What does request. get. get mean?
I see something like this in django
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 class, which can be useful when some instantiation.
Powershell's get-adgroupmember cmdlet returns members of a specific group.
Is there a cmdlet or property to get all the groups that a particular user is a member of?
Ultimately it probably doesn't have a safe. get method because a dict is an associative collection (values are associated with names) where it is inefficient to check if a key is present (and return its value).