Given that it is relevant to their research, they should consider learning how to code.

Otherwise you'll be at the mercy of whatever autogenerated code that you happen to be using, since you literally don't have the skill to check if it's actually working.

The other alternative is to work with a programmer.

this is new technologies, and there are no scientists have salary higher than programmers

I want to echo this point.

Our 'salary' was ~$24k/year. So, just enough to stay alive and for a beer on Fridays.

If my co-researcher had the coding abilities he needed, he would have left.

And, apologies if I wasn't clear enough here, we were grad students.