Flask 面试题与答案

问题 26. How to debug a Flask application?

We can debug the Flask application. Every development server has a debugging facility. Flask also comes with one server, so one server is there by default. If we run the method to call the Flask application object, we need to keep the debug mode value true. 

Remember that we need to deactivate the debug mode before deploying; otherwise, a full stack trace will be displayed in a browser. It is not secure as it has confidential details. One extension is also available named Flask-DebugToolbar.

问题 27. Tell about the identifiers in Flask.

Actually, it can be any length. But there are certain rules which we must follow:

1. The identifier should start with a  character or an underscore, or from A-Z or a-z.
2. A-Z or a-z can be stored as a name in the identifier.
3. Python Flask is case-sensitive.
4. Few keywords are not usable in identifiers like and, false, import, true, del, try, etc.

问题 28. How many HTTP methods can we use in Flask?

Basically, we use 5 types of HTTP methods to retrieve data from URLs. They are:

1. GET: It sends the unencrypted data to the server.
2. POST: Post server caches all data except HTML.
3. HEAD: It is similar to GET without any response body.
4. PUT: It can replace current data.
5. DELETE: It can delete the current data requested by any URL.

问题 29. What is the procedure for database connection requests in Flask?

We can do it in three ways, they are:

1. after_request(): It helps make a request and passes the response, which will be sent to the client.
2. before-request(): It is called before the request without any argument passing.
3. teardown_request(): In case we get an exception, then this connection will be used and response is not guaranteed.

问题 30. How can we create request context in the flask?

It can be created in two easy steps. They are:

1. It can be created on its own when the application receives a request from the system.
2. We can do it manually by calling app.test_request_context