If you build an application based on (still in use) web2py, extend web2py, or integrate with the web2py source, then it will obey the GPL V2. If you use web2py as a tool and are not related to the product you use it with, you should be fine.
Be careful with shipping and mailing. To be compatible with GPL 2.0, you must release the full source and assembly code if you create a "distribution". If you send it to someone, share it or sell it, you may well expose your code to GPL 2.0. If you host this on a server for private hosting or contract with someone else to work on it, you are most likely not subject to these conditions.
Jacob
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