import sys, os

#set up psycopg2 environment
import psycopg2

def river_dist_matrix(table_name):

    #driving_distance module
    query = """
        select *
        from pgr_drivingDistance ($$
            select
                id as id,
                source::int4 as source,
                target::int4 as target,
                shape_leng::double precision as cost
            from public.'table_name'
            $$, %s, %s, %s, %s
        )
    """

    #make connection between python and postgresql
    conn = psycopg2.connect("dbname = 'routing_test' user = 'postgres' host = 'localhost' password = 'xxxx'")
    cur = conn.cursor()

    #count rows in the table
    cur.execute("select count(*) from 'table_name'")
    result = cur.fetchone()
    k = result[0] + 1                #number of points = number of segments + 1
    print k

    #run loops
    rs = []
    i = 1
    while i <= k:
        cur.execute(query, (i, 100000000000, False, False))
        rs.append(cur.fetchall())
        i = i + 1
    # print rs
    #import csv module
    import csv
    import tempfile
    import shutil

    j = 0
    h = 0
    ars = []
    element = list(rs)
    # print element
    #export data to every row
    filename = 'ck_dist_m.csv'
    with open(filename, 'wb') as f:
        writer = csv.writer(f, delimiter = ',')
        while j <= k - 1:
            while h <= k - 1:
                rp = element[j][h][3]
                ars.append(rp)
                h = h + 1
            else:
                h = 0
                writer.writerow(ars)
                ars = []
            j = j + 1

    # concerning about flow-connection
    with open(filename, 'rb') as f, tempfile.NamedTemporaryFile(mode='wb', delete=False) as g:
        writer = csv.writer(g, delimiter = ',')
        for row in csv.reader(f):
            row = [element if float(element) < 10**6 else 'nan' for element in row]
            writer.writerow(row)

    shutil.move(g.name, filename)


    conn.close()



if __name__ == "__main__":

    table_name = 'tc_500wa'
    river_dist_matrix(table_name)

Traceback (most recent call last):
  File "C:UsersHeinzDesktopriver_dist_matrix.py", line 95, in <module>
    river_dist_matrix(table_name)
  File "C:UsersHeinzDesktopriver_dist_matrix.py", line 40, in river_dist_matrix
    cur.execute("select count(*) from 'table_name'")
psycopg2.ProgrammingError: syntax error at or near "'table_name'"
LINE 1: select count(*) from 'table_name'
                             ^

[Finished in 0.2s]