Changes

Z:/PatentAddress

*Five features (addrline1, addrline2, city, country, postcode) in the table contains address information.

*Features addrline1, addrline2 and city are not cleaned. They have city, country and postcode information.

*By now, we only focus on and clean American patents.

U.S. post code follows the pattern [five digits] or [five digits - four digits]. U.S. patents can be extracted by searching for post code following these patterns using regular expression. Some other countries also use [five digits] for post code, so only post codes following [five digits - four digits] are extracted.