Sounds like this is your first snake and you're just unfamiliar with the normal realities of them.
The eye is clear and bright and that rules out any of the potential issues which 'sometimes cloudy eyes' could relate to. If you give timeframes it'll be easier to say, but normally they'll have cloudy eyes for a few days during the 10 days or so before they slough. The eyes will clear up before the actual slough.
Actual lethargy is a critical sign something is urgently wrong, but I'm guessing you just mean your snake isn't particularly active. That's normal, he's an adult python. They naturally spend days, weeks, sometimes even months sitting hidden away doing literally nothing. If he seems to be weak and have trouble moving then by all means panic in an irrational frenzy, but if you just mean he isn't doing much, don't worry, he's just doing what he is supposed to.
An adult male python not eating for a couple of weeks is normal. I would usually only feed an adult male python about 5-20 times per year. I had one adult male Antaresia in perfect health not want to eat for over a year, which included two breeding seasons, and he fathered babies in both. He stopped feeding around this time of year (perfectly normal), bred that winter, didn't want to feed the following spring or summer, bred again the next winter, and then late in the following spring he decided he wanted to eat again. Snakes don't eat very much, and pythons don't eat much even by snake standards, and males don't eat as much as females.
You haven't given much information at all but it sounds like everything is completely normal
Snakes are unusual creatures, sometimes people expect them to be normal, and when they're not it freaks them out