I have a python application that relies on a file that is downloaded by a client from a website.
The website is not under my control and has no API to check for a "latest version" of the file.
Is there a simple way to access the file (in python) via a URL and check it's date (or size) without having to download it to the clients machine each time?
update: Thanks to those who mentioned the"last-modified" date.  This is the correct parameter to look at.
I guess I didn't state the question well enough.  How do I do this from a python script?  I want to application to check the file and then download it if (last-modified date < current file date).
There is no reliable way to do this.  For all you know, the file can be created on the fly by the web server and the question "how old is this file" is not meaningful.  The webserver may choose to provide Last-Modified header, but it could tell you whatever it wants.
How can I get the created date of a file on the web (with Python)?