Creating class instance from module and class name

[gentlestone]

Suppose I've saved the class name and (don't know how) I've also saved
the Class's module (package path or I don't know what's the name for
XYZ "from X.Y.Z import ...). How can I construct a new class according
to saved informations? If I don't know what Class it could be, only I
have the saved Class name?