import psycopg2
import sys
...
con = None

try:
port="5432")
    con = psycopg2.connect(database=DB_NAME, user=DB_USER, password=DB_PASS, host=DB_HOST, port=DB_PORT)
    cur = con.cursor()
    cur.execute('SELECT schema_name FROM public.boundaries WHERE active = TRUE')
    rows = cur.fetchall()
    print "rows = ", rows
    for row in rows:
        cur1 = con.cursor()
        cur1.execute("SELECT count(*) FROM INFORMATION_SCHEMA.tables WHERE table_schema = 'public' AND table_name = 'tb_alter_cid_log'")
        cnt = cur1.fetchone()
        if cnt:
          if cnt[0] == 0:
             cur2 = con.cursor()
             cur2.execute('CREATE TABLE public.tb_alter_cid_log (sch_name text COLLATE "default", tb_name  text COLLATE "default", tb_date  text, altering_coment text COLLATE "default", complete_time timestamptz(6)) WITH (OIDS=FALSE)')
             con.commit()
             cur2.close()

        cur3 = con.cursor()
        cur3.execute('SELECT COUNT(*) FROM public.tb_alter_cid_log')
        cnt3 = cur3.fetchone()
        if cnt3[0] == 0:
            print "cnt3 = ", cnt3[0]
            cur4 = con.cursor()
            print "schema_name = ", row[0]
            cur4.execute("SELECT SUBSTR(table_name,4,length(table_name)) FROM information_schema.tables WHERE table_schema = %s AND (table_name LIKE 'pr_%%' AND table_name NOT LIKE 'pr_st_%%' AND table_name NOT LIKE '%%_rp_%%') ORDER BY 1",(row[0],))
            rows4 = cur.fetchall()
            print "rows4 = ", rows4
            for row4 in rows4:
                print "date_num = ", row4[0]

except psycopg2.DatabaseError, e:
    print 'Error %s' % e
#           pass
    sys.exit(1)

finally:
    if con:
        con.close()

rows =  [('bz_00',)]
cnt3 =  0
schema_name =  bz_00
rows4 =  []

Process finished with exit code 0

SELECT SUBSTR(table_name,4,length(table_name)) FROM information_schema.tables WHERE table_schema = 'bz_00' AND (table_name LIKE 'pr_%' AND table_name NOT LIKE 'pr_st_%' AND table_name NOT LIKE '%_rp_%') ORDER BY 1