Module phonenumber

source code

Code for normalising and formatting phone numbers

This doesn't (yet) try to deal with international numbers. The rule is that if the string contains 10 digits (with an optional preceding one) then it is reduced to the 10 digits (all non-digit characters removed, optional leading one removed).

If the string doesn't meet those criteria then it is passed through as is.

For formatting, 10 digit strings are formatted in standard US notation. All others are left as is.