from osgeo import ogr
import sys

databaseServer = "postgrestest1"
port = "5433" # <-- I know default is 5432, bu this server uses 5433
databaseName = "pgv_2017"
databaseUser = "myname"
databasePW = "mypassw"
connString = "PG: host=%s port=%s dbname=%s user=%s password=%s"    %(databaseServer,port,databaseName,databaseUser,databasePW)

lyr_name = "k.jis"


def GetPGLayerFields( lyr_name ):
    conn = ogr.Open(connString)
    print "conn:", conn

    lyr = conn.GetLayer( lyr_name )
    print "lyr:", lyr

    lyrDefn = lyr.GetLayerDefn()
    print "lyrDefn:", lyrDefn

    num_flds = lyrDefn.GetFieldCount()
    print "num_flds:", num_flds

    for i in range(num_flds):
        print lyrDefn.GetFieldDefn( i ).GetName()

    conn.Destroy()


if __name__ == '__main__':

    GetPGLayerFields( lyr_name )

C:MartinWork>python test_pg_connect.py
conn: <osgeo.ogr.DataSource; proxy of <Swig Object of type 'OGRDataSourceShadow *' at 0x00000000021C0720> >
lyr: <osgeo.ogr.Layer; proxy of <Swig Object of type 'OGRLayerShadow *' at 0x00000000021C0660> >
lyrDefn: <osgeo.ogr.FeatureDefn; proxy of <Swig Object of type 'OGRFeatureDefnShadow *' at 0x0000000004541030> >
num_flds: 0

C:MartinWork>