Your module and your class AthleteList
have the same name. The line
import AthleteList
imports the module and creates a name AthleteList
in your current scope that points to the module object. If you want to access the actual class, use
AthleteList.AthleteList
In particular, in the line
return(AthleteList(templ.pop(0), templ.pop(0), templ))
you are actually accessing the module object and not the class. Try
return(AthleteList.AthleteList(templ.pop(0), templ.pop(0), templ))