Well, it's a property of circle object. As JS is a dynamically typed language you have to either handle cases if there's no such property, or hope that everything will be okay ;)

As for Python, PEP8 says:
'Function names should be lowercase, with words separated by underscores as necessary to improve readability.'

Test failed, though submission was successful in Python?

Python version, and perhaps other as well, requires function to be named remove_char, while it is not mentioned in the description.

Thanks for reply. As for the style, it is not about what is doable, but what is the best practive. See for example:
http://www.sqlstyle.guide/
https://github.com/meadmaker/sql-style-guide

Following style rules like above allows to communicate effectively your code.

Sweet gods of query, that was fantastic! I am looing forward to more of your challenges.

To improve this one, I upvote for clearer description and prevention of using predetermined actors id to return the desired data.

Every query of currency table results in the below:

PG::UndefinedTable: ERROR: relation "currency" does not exist
LINE 1: SELECT count(*) AS "count" FROM (SELECT * FROM CURRENCY) AS ...

Moreover, please work on SQL style (like please don't name tables in UPPERCASES) as well as clarity of the question itself. Analysing existing approved SQL katas would give you strong impression how they should look like. Good luck with improving!

Could please anyone advise, just for expanding our knowledge, how to make the table DISPLAY up to two decimal places? Meaning if a row returns 12.3, I would like to see 12.30. Much appreciated!