So there is a heavy weight on the outside for generating energy; and for beating your kid on the side of the head if he ever dares to walk too close to you.
Not that I pay attention to such things, but purses have been available with interior lights for some time now. They are activated by the magnetic clasp; when it is pulled open the light goes on, when the clasp catches it goes off. A small battery can power the LED for hundreds of hours, eliminating the need for a complicated power generation source.