I'm using Pygal (with Python / Flask) relatively successfully in regards to loading data, formatting colors, min/max, etc., but can't figure out how to format a number in Pygal using dollar signs and commas.  
I'm getting 265763.557372895 and instead want $265,763.
This goes for both the pop-up boxes when hovering over a data point, as well as the y-axes.  
I've looked through pygal.org's documentation to no avail.  Does anyone know how to properly format those numbers?
UPDATE:
I'm not quite ready to mark this question "answered" as I still can't get the separating commas.  However, I did find the following native formatting option in pygal.  This eliminates trailing decimals (without using Python's int()) and adds a dollar sign:
graph.value_formatter = lambda y: "$%.0f" % y
Change the 0f to 2f if you prefer two decimals, etc.
graph.value_formatter = lambda y: "{:,}".format(y) will get you the commas.
graph.value_formatter = lambda y: "${:,}".format(y) will get you the commas and the dollar sign.
Note that this formatting seems to be valid for Python 2.7 but would not work on 2.6.
Properly formatting numbers in pygal