Attaching Text on chart location

Hi there,

I am using matplotlib for the first time to chart stock prices.

I have a list of trades I have made on a particular stock, and I would
like to be able to superimpose on the chart the particular "buy" or
"sell" days I have made historically.

I had a look at the "plt.text()" function, but not sure about the x,y
portion, since the two items I am interested in are the date (x-axis)
and price (y-axis) for that trade to put a "buy" or "sell" label on.

The buy/sell data I have in a MySQL DB, but easily pulled into a list or
array if matplotlib lends itself to either format.

Any tips or help appreciated.