import psycopg2
    import psycopg2.extensions
    import sys

    def main():
        proyecto="host='localhost' dbname='api' user='postgres' password='123456789'"
        obj= psycopg2.connect(proyecto)
        cur=obj.cursor()
        cura= "SELECT * FROM public."pensum" WHERE "Id.Carrera" = %s "
        a= 1
        cur.execute(cura,[a])
        a2=cur.fetchone()
        print(a2)

    main()

id.carrera |        clase
    -----------------------------
    ( 1         ,'TRABAJO DE GRADO')

id.carrera |        clase
    -----------------------------
    1          ;"TRABAJO DE GRADO"
    1          ;"CATEDRA UDECINA"
    1          ;"CONSTITUCION Y DEMOCRACIA"
    1          ;"DEPORTES"

cur.execute(cura,[a])
for a2 in cur.fetchall()
    print(a2)

cur.execute(cura,[a])
while True:
    rows = cur.fetchmany(5)
    if not rows:
        break

    for row in rows:
        print(row)

cur.execute(cura,[a])
a2 = cur.fetchone()
while (a2 != None):
   print (a2)
   registro = cur.fetchone()

for a2 in cur.execute(cura,[a]):
    print (a2)