小编The*_*eer的帖子

我跟着一本书尝试创建Flask博客。我是Flask的新手。我更新了一个模型，因此代码如下所示：

class Entry(db.Model):
    STATUS_PUBLIC = 0
    STATUS_DRAFT = 1
    STATUS_DELETED = 2

    id = db.Column(db.Integer, primary_key=True)
    title = db.Column(db.String(100))
    slug = db.Column(db.String(100), unique=True)
    body = db.Column(db.Text)
    status = db.Column(db.SmallInteger, default=STATUS_PUBLIC)
    created_timestamp = db.Column(db.DateTime, default=datetime.datetime.now)
    modified_timestamp = db.Column(
        db.DateTime,
        default=datetime.datetime.now,
        onupdate=datetime.datetime.now)
    author_id = db.Column(db.Integer, db.ForeignKey("user.id"))

添加最后一行author_id = db.Column(db.Integer, db.ForeignKey("user.id"))会导致数据库升级失败，并显示以下错误：

  File "manage.py", line 5, in <module>
    manager.run()
  File "/home/devblog/projects/blog/venv/lib/python2.7/site-packages/flask_script/__init__.py", line 412, in run
    result = self.handle(sys.argv[0], sys.argv[1:])
  File "/home/devblog/projects/blog/venv/lib/python2.7/site-packages/flask_script/__init__.py", line 383, in handle
    res = handle(*args, **config)
  File "/home/devblog/projects/blog/venv/lib/python2.7/site-packages/flask_script/commands.py", line …

我尝试安装 PyLint。安装时我看到以下内容：

Collecting pylint\n  Downloading pylint-1.6.5-py2.py3-none-any.whl (577kB)\n    100% |\xe2\x96\x88\xe2\x96\x88\xe2\x96\x88\xe2\x96\x88\xe2\x96\x88\xe2\x96\x88\xe2\x96\x88\xe2\x96\x88\xe2\x96\x88\xe2\x96\x88\xe2\x96\x88\xe2\x96\x88\xe2\x96\x88\xe2\x96\x88\xe2\x96\x88\xe2\x96\x88\xe2\x96\x88\xe2\x96\x88\xe2\x96\x88\xe2\x96\x88\xe2\x96\x88\xe2\x96\x88\xe2\x96\x88\xe2\x96\x88\xe2\x96\x88\xe2\x96\x88\xe2\x96\x88\xe2\x96\x88\xe2\x96\x88\xe2\x96\x88\xe2\x96\x88\xe2\x96\x88| 583kB 655kB/s \nCollecting six (from pylint)\n  Using cached six-1.10.0-py2.py3-none-any.whl\nCollecting isort>=4.2.5 (from pylint)\n  Downloading isort-4.2.5-py2.py3-none-any.whl (40kB)\n    100% |\xe2\x96\x88\xe2\x96\x88\xe2\x96\x88\xe2\x96\x88\xe2\x96\x88\xe2\x96\x88\xe2\x96\x88\xe2\x96\x88\xe2\x96\x88\xe2\x96\x88\xe2\x96\x88\xe2\x96\x88\xe2\x96\x88\xe2\x96\x88\xe2\x96\x88\xe2\x96\x88\xe2\x96\x88\xe2\x96\x88\xe2\x96\x88\xe2\x96\x88\xe2\x96\x88\xe2\x96\x88\xe2\x96\x88\xe2\x96\x88\xe2\x96\x88\xe2\x96\x88\xe2\x96\x88\xe2\x96\x88\xe2\x96\x88\xe2\x96\x88\xe2\x96\x88\xe2\x96\x88| 40kB 737kB/s \nCollecting mccabe (from pylint)\n  Downloading mccabe-0.6.1-py2.py3-none-any.whl\nCollecting configparser; python_version == "2.7" (from pylint)\n  Downloading configparser-3.5.0.tar.gz\nCollecting backports.functools-lru-cache; python_version == "2.7" (from pylint)\n  Downloading backports.functools_lru_cache-1.3-py2.py3-none-any.whl\nCollecting astroid<1.5.0,>=1.4.5 (from pylint)\n  Downloading astroid-1.4.9-py2.py3-none-any.whl (213kB)\n    100% |\xe2\x96\x88\xe2\x96\x88\xe2\x96\x88\xe2\x96\x88\xe2\x96\x88\xe2\x96\x88\xe2\x96\x88\xe2\x96\x88\xe2\x96\x88\xe2\x96\x88\xe2\x96\x88\xe2\x96\x88\xe2\x96\x88\xe2\x96\x88\xe2\x96\x88\xe2\x96\x88\xe2\x96\x88\xe2\x96\x88\xe2\x96\x88\xe2\x96\x88\xe2\x96\x88\xe2\x96\x88\xe2\x96\x88\xe2\x96\x88\xe2\x96\x88\xe2\x96\x88\xe2\x96\x88\xe2\x96\x88\xe2\x96\x88\xe2\x96\x88\xe2\x96\x88\xe2\x96\x88| 215kB 713kB/s \nCollecting lazy-object-proxy (from astroid<1.5.0,>=1.4.5->pylint)\n  Downloading lazy-object-proxy-1.2.2.tar.gz\nCollecting wrapt (from astroid<1.5.0,>=1.4.5->pylint)\n  Downloading wrapt-1.10.8.tar.gz\nBuilding wheels for collected packages: configparser, lazy-object-proxy, wrapt\n  Running …