Retrieve the complete list of RICs of an exchange using Eikon Data Python API?

For exchange identifiers in the screener we use MIC or Market Identifier Code (ISO 10383). For a more generic use case follow the Screener wizard in Eikon Excel. Click on the Screener button in Thomson Reuters ribbon in Eikon Excel. Follow the wizard to select your equity screening criteria, then click Insert Screener button. This will insert =TR function into Excel worksheet. The screener expression can be copied and pasted from this formula into your Python code. This is exactly what I did to create the example above.

The equity screener expression in the above example excludes non primary and dual listings. To include dual listings in the result use

ek.get_data('SCREEN(U(IN(Equity(active,public,primary,countryprimaryquote))/*UNV:Public*/), IN(TR.ExchangeMarketIdCode,"XHKG"))',['TR.CommonName'])

For help with creating equity screener expressions follow the Screener wizard in Eikon Excel. You may also want to watch video tutorial titled "Creating Data Retrieval Functions using Equity Screener" available from the main Eikon menu - Help - Tutorials and Training.

I don't believe this is possible in Eikon. See my comments on a previous thread on similar subject.
https://community.developers.refinitiv.com/comments/28509/view.html