Thank you for the suggestion. In fact, the first version conda downloaded was PyStan 2.x, which didn’t work. Then, I realized I had to install Stan with pip, and it installed PyStan 3.x, which has worked well so far.
The problem with having CmdStan and PyStan is not whether it is hard to use or not, but the uncertainty you are in. Why two interfaces? If I switch to CmdStan, will I regret some functionality I had in PyStan? and, what if one version misses something the other has, and the other way around? I recently started learning Bayesian statistics for my job, and I have many other things I must pay attention to, so this is an additional unwanted distraction. I’d like to know the difference, and a quick google search didn’t yield much.
Don’t take it bad, I thank the Stan community for releasing this amazing software I am enjoying for free; online interaction lacks the facial feedback we need to have healthy conversations.