└── schemas.py
```

该文件`__init__.py`只是一个空文件，但它告诉 Python `sql_app` 是一个包。

现在让我们看看每个文件/模块的作用。

## 安装 SQLAlchemy

首先你需要安装`SQLAlchemy`:

<div class="termy">

```console
$ pip install sqlalchemy

---> 100%
```

</div>

## 创建 SQLAlchemy 部件

让我们转到文件`sql_app/database.py`。

### 导入 SQLAlchemy 部件

```Python hl_lines="1-3"

    your build system.

    OkHttp will use Conscrypt if you set the `okhttp.platform` system property
    to `conscrypt`.

    Alternatively, OkHttp will also use Conscrypt if you install it as your
    preferred security provider. To do so, add the following code to execute
    before you create your `OkHttpClient`.

    ```
    Security.insertProviderAt(

    /** The key of the message: {0} is not found. */
    public static final String ERRORS_plugin_file_is_not_found = "{errors.plugin_file_is_not_found}";

    /** The key of the message: Failed to install {0}. */
    public static final String ERRORS_failed_to_install_plugin = "{errors.failed_to_install_plugin}";

    /** The key of the message: Failed to access available plugins. */

it requires installation of the OpenStack Cinder CSI Driver. The in-tree AWS OpenStack Cinder driver "kubernetes.io/cinder" was deprecated in 1.16 and will be removed in 1.20. Users should enable CSIMigration + CSIMigrationOpenStack features and install the OpenStack Cinder CSI Driver (https://github.com/kubernetes/cloud-provider-openstack) to avoid disruption to existing Pod and PVC objects at that time. Users should start using the OpenStack Cinder CSI Driver directly for any new volumes. ([#8...

- `kube-proxy`: Added an option/flag for configuring the `nf_conntrack_tcp_be_liberal` sysctl (in the kernel's netfilter conntrack subsystem).  When enabled, `kube-proxy` will not install the `DROP` rule for invalid conntrack states, which currently breaks users of asymmetric routing. ([#120354](https://github.com/kubernetes/kubernetes/pull/120354), [@aroradaman](https://github.com/aroradaman))

### Feature

*   You now have the option to use CoreDNS instead of KubeDNS. To install CoreDNS instead of kube-dns, set CLUSTER_DNS_CORE_DNS to 'true'. This support is experimental. ([#52501](https://github.com/kubernetes/kubernetes/pull/52501),[ @rajansandeep](https://github.com/rajansandeep)) ([#55728](https://github.com/kubernet...

   e) Provide Installation Information, but only if you would otherwise
   be required to provide such information under section 6 of the
   GNU GPL, and only to the extent that such information is
   necessary to install and execute a modified version of the
   Combined Work produced by recombining or relinking the
   Application with a modified version of the Linked Version. (If

  for actions against a CRI endpoint. The kubeadm deb/rpm packages will continue to install the `cri-tools`
  package for one more release, but in you must adapt your scripts to install `crictl` manually from
  https://github.com/kubernetes-sigs/cri-tools/releases or a different location.
  

  
  Users that self-deploy Kubernetes on vSphere should enable CSIMigration + CSIMigrationvSphere features and install the vSphere CSI Driver (https://github.com/kubernetes-sigs/vsphere-csi-driver) to avoid disruption to existing Pod and PVC objects at that time. Users should start using the vSphere CSI driver directly for any new volumes.
  

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  <mime-type type="application/vnd.nokia.pcd+xml"/>