export.py

#!/usr/bin/env python
# -*- coding: utf-8 -*-

import psycopg2

con = psycopg2.connect("dbname=nyc3 user=postgres") # CONnect to a database
cur = con.cursor()

cur.execute('''select ctidfp00 from tracts;''')
results = cur.fetchall()

for result in results:
    tract_id = result[0] # create a variable from the first column of the results
    cmd = ''.join([
        'pgsql2shp -u postgres -f tract_', tract_id, ' nyc3 ',
        '"select a.gid,a.the_geom,a.overlap from import_buildings a ',
        'where st_dwithin(a.the_geom, (select b.the_geom from tracts b where cast(ctidfp00 as numeric) = ', tract_id, '), 0);"',
        ])
    print(cmd)

cur.close()
con.close()
test_tract_building.py (END)