MatPlotLib question: How to get more different size plot symbols ?

[Dr. Colombes]

MatPlotLib question:  How to get more different size plot symbols in
the plot function ?

Is there a way to get different size squares (or circles or triangles,
etc.) ?

For example, in a two dimensional plot of heights and weights of
individuals, is there a way to represent also the age of the
individual by the size of the plot symbol ?

Thanks for your help.