标签： Python Flask

【参考链接】
Flask – ImportError: No module named migrate.versioning

跟着欢迎进入Flask大型教程项目！的教程学习Flask，到了数据库迁移的时候，运行脚本出错，这是迁移脚本的内容，运行后报:

ModuleNotFoundError: No mudule named ‘migrate’

迁移脚本代码：

import imp
from migrate.versioning import api
from app import db
from config import SQLALCHEMY_DATABASE_URI, SQLALCHEMY_MIGRATE_REPO

v = api.db_version(SQLALCHEMY_DATABASE_URI, SQLALCHEMY_MIGRATE_REPO)
migration = SQLALCHEMY_MIGRATE_REPO + ('/versions/%03d_migration.py' % (v + 1))

tmp_module = imp.new_module('old_model')
old_model = api.create_model(SQLALCHEMY_DATABASE_URI, SQLALCHEMY_MIGRATE_REPO)

exec(old_model, tmp_module.__dict__)

script = api.make_update_script_for_model(SQLALCHEMY_DATABASE_URI,
                                           SQLALCHEMY_MIGRATE_REPO,
                                           tmp_module.meta,
                                           db.metadata)
open(migration, "wt").write(script)
api.upgrade(SQLALCHEMY_DATABASE_URI, SQLALCHEMY_MIGRATE_REPO)

v = api.db_version(SQLALCHEMY_DATABASE_URI, SQLALCHEMY_MIGRATE_REPO)

print('New migration saved as ' + migration)
print('Current database version: ' + str(v))

这时候只需要执行:

pip install sqlalchemy
pip install sqlalchemy-migrate

将这两个库安装上即可。