The code sets up a Flask web application with multiple routes that return different responses depending on the URL accessed. When the application is run, Flask starts a local development server. The output includes web pages with messages specified in the route functions, personalized greetings using URL parameters, error handling, and JSON responses to POST requests containing calculated results.

1. Flask Interview
Questions
By pythongeeks

2. The code sets up a basic Flask web application with a single route that maps to
the root URL (“/”) and returns the string “Hello, World!” when accessed. When the
application is run using app. run(), Flask starts a local development server, and the
output will be a web page displaying the message “Hello, World!”.
1. What is the output of the following Flask code?
2. What is the output of the following Flask code?
The code sets up a Flask web application with two routes. The first route maps to
the root URL (“/”) and returns the string “Hello, World!” when accessed. The
second route maps to “/about” and returns the string “This is the About page.”
when accessed. When the application is run using app.run(), Flask starts a local
development server, and the output will be a web page displaying the message
“Hello, World!” when accessed at the root URL, and “This is the About page.” when
accessed at “/about”.

3. The code sets up a Flask web application with a single route that maps to the
root URL (“/”) and returns the string “Hello, World!” when accessed. The
debug=True argument passed to app.run() enables the Flask debugger, which
provides detailed error messages and reloads the application on changes. When
the application is run using app.run(debug=True), Flask starts a local development
server with the debugger enabled, and the output will be a web page displaying
the message “Hello, World!”.
3. What is the output of the following Flask code?
4. What is the output of the following Flask code?
The code sets up a Flask web application with two routes. The first route maps to
the root URL (“/”) and returns the string “Hello, World!” when accessed. The second
route maps to “/user/<username>”, where <username> is a dynamic URL parameter
that can capture any string entered in the URL, and returns a personalized greeting
message using the captured value. For example, if the URL is accessed with
“/user/john”, the output will be “Hello, john!”.

4. The code sets up a Flask web application with three routes. The first route maps to
the root URL (“/”) and returns the string “Hello, World!” when accessed. The second
route maps to “/user/<username>”, where <username> is a dynamic URL parameter
that can capture any string entered in the URL, and returns a personalized greeting
message using the captured value. The third route uses the @app.errorhandler
decorator to handle 404 errors, which occur when a user tries to access a page that
doesn’t exist.
The error handler returns the string “Page not found” with a 404 status code. When
the application is run using app.run(), Flask starts a local development server, and
the output will be a web page displaying the message “Hello, World!” when
accessed at the root URL, and personalized greeting messages or “Page not found”
error message when accessing other URLs based on the defined routes and error
handler.
5. What is the output of the following Flask code?

5. The code sets up a Flask web application with two routes. The first route maps to
the root URL (“/”) and returns the string “Hello, World!” when accessed. The second
route maps to “/greet/<name>”, where <name> is a dynamic URL parameter that
can capture any string entered in the URL, and returns the result of rendering a
template called “greet.html” with the name variable passed to it.
The template “greet.html” should be created separately and should contain HTML
code, which will be rendered and returned as the output. The specific output will
depend on the content of the “greet.html” template.
6. What is the output of the following Flask code?

6. The code sets up a Flask web application with two routes. The first route maps to
the root URL (“/”) and returns the string “Hello, World!” when accessed. The second
route maps to “/redirect” and uses the redirect() and url_for() functions from Flask
to redirect the user to the “hello” function, which maps to the root URL (“/”).
When the application is run using app.run(), Flask starts a local development server,
and the output will be a web page displaying the message “Hello, World!” when
accessing either the root URL or the “/redirect” URL, as both will redirect to the
“hello” function.
7. What is the output of the following Flask code?

7. The code sets up a Flask web application with a single route that maps to the root
URL (“/”) and returns a personalized greeting message using the request object
from Flask. The request.args.get() method is used to retrieve the value of the
“name” query parameter from the URL. If the “name” parameter is not present in
the URL, the default value of “World” will be used. When the application is run
using app.run(), Flask starts a local development server, and the output will be a
web page displaying the message “Hello, World!” when accessing the root URL (“/”).
However, if a “name” parameter is included in the URL, the value of the “name”
parameter will be used in the greeting message instead of the default “World”.
8. What is the output of the following Flask code?

8. The code sets up a Flask web application with a single route that maps to the
“/add” URL and accepts only POST requests. The route expects two integer values,
“num1” and “num2”, to be passed as form data in the request body. The values are
retrieved using the request.form dictionary from Flask, and then added to calculate
a result. The result is then returned as a JSON response using the jsonify() function
from Flask.
When the application is run using app.run(), Flask starts a local development server.
To test the code and see the output, a POST request needs to be made to the “/add”
URL with valid “num1” and “num2” values in the request body, and the response will
be a JSON object containing the calculated result.
9. What is the output of the following Flask code?

9. The code sets up a Flask web application with a single route that maps to the
“/multiply” URL and accepts only POST requests. The route expects two integer
values, “num1” and “num2”, to be passed as form data in the request body. The
values are retrieved using the request.form dictionary from Flask, and then
multiplied to calculate a result. The result is then returned as a JSON response
using the jsonify() function from Flask.
When the application is run using app.run(), Flask starts a local development server.
To test the code and see the output, a POST request needs to be made to the
“/multiply” URL with valid “num1” and “num2” values in the request body, and the
response will be a JSON object containing the calculated result.
10. What is the output of the following Flask code?