[Serusers] Questions about strip() and altering ANI/From: numbers

When using strip() on a E.164 format number (eg +17895551212), does strip(2) delete the +1, or is it going to delete "17" in the shown example? I seem to be getting the latter behavior. If the latter is what is intended, how does one get rid of the plus? Second, is there something equivalent to strip() for editing the ANI/From: number? As I am doing PSTN gateway conversions, I have to strip the +1 from a E.164 ANI/From: (if sent) at some point so that the destination PSTN switch can correctly do the Calling Name database lookup. The North American Calling Name databases will only match if exactly ten digits are provided, so the ANI/From: has to be scrubbed down to ten digits if the country code in the ANI/From: begins with +1. Thanks!