Help with an SNMP check: fine on cli, no output on web

First thing - it would be good to see how your info looks like. (the value of the info variable from your inventory function)
Second point is “yield” at the end without a loop means only one value returned.
It would be better to use a return there instead of yield.
Also there should be no print statement inside of inventory function.
Other thing is I don’t understand what you want to achieve with your many appends?