How Can I Increase the Speed of a Large Number of Date Conversions

[vdicarlo]

Many thanks for the lucid and helpful suggestions. Since my date range
was only a few years, I used Some Other Guy's suggestion above, which
the forum is saying will be deleted in five days, to make a dictionary
of the whole range of dates when the script starts. It was so fast it
wasn't even worth saving in a file. Made the script a LOT faster. I
guess two thousand function calls must be faster than 200 million?
Like maybe a hundred thousand times faster?

I also benefitted from studying the other suggestons. I had actually
implemented an on the fly dictionary caching scheme for one of my
other calculations. I don't know why it didn't occur to me to do it
with the dates, except I think I must be assuming, as a newbie
Pythonista, that the less I do and the more I let the libraries do the
better off I will be.

Thanks for putting me straight. As someone I know said to me when I
told him I wanted to learn Python, "the power of Python is in the
dictionaries".

Funny how long it's taking me to learn that.