Python sqlalchemy.engine.base.engine COMMIT在运行seed程序后显示在终端中，但在查询表时不显示数据

我已经编写了一个种子程序，使用SQLAlchemy模式将数据种子植入PostgreSQL。我创建了一个“课程”表，其中包含id、组织、标题、作者、开始日期、结束日期、持续时间和日程安排注释

当我运行程序时，我会看到insert命令和插入的信息，然后是COMMIT语句。然而，当我打开PostgreSQL并运行“select*from courses”时，我什么也得不到。桌子是空的

以下是我运行程序时在终端中看到的内容：

2015-02-18 16:28:17353信息sqlalchemy.engine.base.engine 2015-02-18 16:28:17353信息sqlalchemy.engine.base.engine插入课程>组织、标题、作者、开始日期、结束日期、持续时间、日程注释值%组织、%标题、%作者、%开始日期、%结束日期、%持续时间、%日程注释返回课程.id 2015-02-18 16:28:17353信息sqlalchemy.engine.base.engine{'schedule_notes'：'没有开放的会议。\n'，'start_date'：无，'duration'：'None'，'title'：'有摩擦的市场'，'authors'：['Randall'，'Wright'，'end_date'：无，'organization'：'University of Wisconsin\xe2\x80\x93Madison'} 2015-02-18 16:28:17354信息sqlalchemy.engine.base.engine提交

这是我的种子.py： 导入模型

import datetime

def load_courses(session):
    # use u.user
    #reads in file and parses data
    users_table = open("courses.txt", "r")
    for line in users_table:
        aline = line.split('\t')
        organization, title, authors, start_date, duration, schedule_notes = aline

        #creates instance of user
        course = model.Course()
        course.title = title
        course.organization = organization
        author_list = authors.split()
        course.authors = author_list

        starting = start_date.split()

        try:
            month, day, year = starting
            day = day.replace(',', '').replace('st', '').replace('th', '').replace('nd', '').replace('rd', '')
            months = {"Jan":1,"Feb":2, "Mar":3,"Apr":4,"May":5,"Jun":6,"Jul":7, "Aug":8, "Sep":9, "Oct":10,"Nov":11,"Dec":12}
            date = datetime.date(int(year), months[month], int(day))
            course.start_date = date
            converted_duration = duration.replace('st', '').replace(' weeks long', '').replace('th', '').replace('nd', '').replace('rd', '')
            lasting = datetime.timedelta(days=((int(converted_duration))*7))
            course.end_date = lasting + date
        except ValueError:
            course.start_date = None
            course.end_date = None

        try:
            course.duration = duration
        except ValueError:
            course.duration = None

        course.schedule_notes = schedule_notes

        print(type(course.end_date))
        # adds course to session
        session.add(course)

        #commits session changes
        session.commit()


def main(session):
    # You'll call each of the load_* functions with the session as an argument
    load_courses(session)

if __name__ == "__main__":
    s= model.connect()
    main(s)

这是my model.py的内容：

from sqlalchemy import create_engine, Column, Integer, String, Date
from sqlalchemy.ext.declarative import declarative_base
from sqlalchemy.engine.url import URL
# from sqlalchemy.dialects import postgresql
from sqlalchemy.orm import sessionmaker, scoped_session
import settings


DeclarativeBase = declarative_base()

ENGINE = create_engine(URL(**settings.DATABASE), echo=True)

session = scoped_session(sessionmaker(bind=ENGINE,
                                        autocommit = False,
                                        autoflush = False))


def connect():
    global ENGINE
    global Session

    ENGINE = create_engine(('postgresql:///courses'), echo=True)
    Session = sessionmaker(bind=ENGINE)

    return Session()


def create_courses_table(engine):
    """"""
    DeclarativeBase.metadata.create_all(engine)


class Course(DeclarativeBase):
    """Sqlalchemy courses model"""
    __tablename__ = "courses"

    id = Column(Integer, primary_key=True)
    organization = Column('organization', String)
    title = Column('title', String)
    authors = Column('authors', String)
    start_date = Column('start_date', Date(timezone=False), nullable=True)
    end_date = Column('end_date', Date(timezone=False), nullable=True)
    duration = Column('duration', Integer, nullable=True)
    schedule_notes = Column('schedule_notes', Integer, nullable=True)

我已经搜索了堆栈溢出，但找不到表存在的任何情况，也没有错误消息，但结果仍然为空

---

任何帮助都将不胜感激。希望我犯了一个简单而愚蠢的错误。

我了解到，为了使数据种子化到表中，我需要手动将一些值插入到表列中

一旦我添加了一行，我就可以使用我的脚本为其余的数据播种

愚蠢的错误