You asked for a programming language that is good for a domainer. What you got as expected is overwhelmed with info that in most cases will lead you nowhere.
Domainers mostly look for name opportunities. If you are of the rare breed that develops sites, ignore my post.
Name opportunities appear on many sites including godaddy, dropcatch, snapnames, namejet, nameliquidate, this forum, sites that curate lists etc.
If you just want to see lists of names from many sites every day, you could visit expireddomain.net free.
If you want to gather data automatically, i.e. scrape, then build your own rules to trigger alerts, keyword placement rules, custom valuation functions, connecting to godaddys api, automatically checking specific pages for domains, searching icanns whois using their simple api etc and 100'smany of small tasks domainers do, you need to learn a programming language.
First thing, everything I just said you could do with C, C++, C#, Java, Go, Python, PHP etc. The question is, what will you reasonably learn and fast.
Most private business people that work with data choose python, it's fast, has a library for everything you could think of including graphs and the learning curve is fast. You don't have to setup a special environment as you would with web development and it has a strong community.
The downside is that for a domainer, unless you learn how to build gui's with python, it will really just burn you out creating csv's, opening them etc. You will want to learn how to use tkinter, a python library to create gui's, for example, for a domainer knowing how to use the datagrid is important.
Most private people that learn python to process data for themselves end up not using it because they fail to learn gui development.
With c# you could build guis fast but the learning curve is a lot more difficult than python.
If you absolutely want to do things using more of a web setup. Meaning, having your own dashboard you go to and run reports based on live data on some other sites plus anything else you could imagine, learn html, javascript, php and mysql, this is a bigger learning curve, however, you can use these skills for a lot more you will ever be able to do with learning python on it's own.
I will say that when you learn python and as domainer need to scrape data, you will automatically have to learn some html and JavaScript.
If you want to get good at it you will have to learn an hour a day and then spend 3 hours playing around with what you learned. After 2 months you will be good enough with programming that you will see ways to do everything more efficient and build fast solutions.
