sqlalchemy tidak mengeksekusi Komentar pada skema

Tidak sepenuhnya yakin mengapa, tetapi tampaknya berfungsi setelah Anda membuat koneksi dan menjalankan COMMIT :

In [8]: conn = engine.connect()                                                                                                                                                                              

In [9]: conn.execute("COMMENT ON SCHEMA myschema IS 'Seemly Random Description'")                                                                                                                            
Out[9]: <sqlalchemy.engine.result.ResultProxy at 0x7fd109991cd0>

In [10]: conn.execute("COMMIT;")                                                                                                                                                                             
Out[10]: <sqlalchemy.engine.result.ResultProxy at 0x7fd0ff3b7d10>

postgres=# \dn+
                            List of schemas
   Name   |  Owner   |  Access privileges   |        Description        
----------+----------+----------------------+---------------------------
 myschema | postgres |                      | Seemly Random Description
 public   | postgres | postgres=UC/postgres+| standard public schema
          |          | =UC/postgres         |