download_zip_data       Download updated data files needed for library
                        functionality to the package's data directory.
                        To be implemented for future updates.
geocode_zip             Returns that lat / lon pair of the centroid of
                        a given ZIP code
get_cd                  Get all congressional districts for a given ZIP
                        code
get_tracts              Get all Census tracts within a given ZIP code
is_zcta                 Returns true if the given ZIP code is also a
                        ZIP code tabulation area (ZCTA)
normalize_zip           Normalize ZIP codes
reverse_zipcode         Given a ZIP code, returns columns of metadata
                        about that ZIP code
search_cd               Get all ZIP codes that fall within a given
                        congressional district
search_city             Search ZIP codes for a given city within a
                        state
search_county           Search ZIP codes for a county
search_fips             Returns all ZIP codes found within a given FIPS
                        code
search_radius           Search for ZIP codes that are within a given
                        radius from a point
search_state            Search for ZIP codes located within a given
                        state
search_tz               Search all ZIP codes located within a given
                        timezone
zcta_crosswalk          ZCTA to Census Tract (2010) Crosswalk
zip_code_db             ZIP Code Database
zip_distance            Calculate the distance between two ZIP codes in
                        miles
zip_to_cd               ZIP Code to Congressional District Relationship
                        File
