migration.py 文件源码

def load_package(self, pkg):
        migrations = []
        for resource_name in pkg_resources.resource_listdir(pkg, "migrations"):
            name, _ = os.path.splitext(resource_name)
            m = MIGRATION_FILE_PATTERN.match(name)
            if m:
                migration = Migration(Version(int(m.group("version")), m.group("name")),
                                      functools.partial(pkg_resources.resource_stream, pkg,
                                                        "migrations/" + resource_name))
                migrations.append(migration)
        self.migrations = sorted(migrations, key=lambda e: e.version.version)