How to change port in flask

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by gayathrimohan dot icon Updated: Oct 10, 2023

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In Flask, the "change port" function specifies the port on which your Flask web app will run. Flask is a Python web framework. People use it to build web applications.

It has a built-in development server that runs on a default port. The "change port" function allows you to specify a different port for your app.  

You can use this function when you want your Flask application to run on a specific port. Changing the port is especially useful when you're deploying your Flask app. The product server undergoes that process.   

Flask change ports, also known as necks or openings. It is an important feature in laboratory glassware for various scientific applications.  

Here's a brief overview of different types of flasks change ports available on the market:  

  • Single-Neck Flask: These flasks have a single opening for adding or removing substances.   
  • Two-Neck Flask: These flasks have two separate necks or openings.   
  • Three-Neck Flask: These flasks have three necks or openings.   
  • Four-Neck Flask: These specialized flasks have four necks or openings.   
  • Round-Bottom Flask: Characterized by a round, spherical shape with a single neck.  
  • Flat-Bottom Flask: It has a flat bottom with a single neck.   
  • Pressure Flask: Designed to withstand high-pressure conditions.   
  • Filter Flask: Features a sidearm or neck with a hose barb to connect to a vacuum source.   
  • Addition Funnel: A specialized flask with a long, narrow neck and a stopcock at the bottom.  
  • Separatory Funnel: Shaped like a funnel with a stopcock at the bottom.  

Flask is a popular Python web framework. The software doesn't have power supplies or temperature sensors. It's specifically for web application development. But I can explain how you might integrate such features into a Flask-based web app:  

  • Power Supplies: To control power supplies, you would need external hardware. Those are like Raspberry Pi or Arduino. You can communicate with these devices using Python libraries. Those libraries are like GPIO or pySerial within your Flask application.   
  • Temperature Sensors: To add these, you would need external hardware. The DHT22 or DS18B20 has an equipped temperature sensor. Flask can serve as the interface for retrieving temperature data and displaying it on a web page.   

Changing the port of a Flask application can offer various benefits:  

  • Efficiency: Changing the port can help avoid conflicts. Many apps run on the same server. By specifying a unique port, you reduce the chances of port collisions. You ensure that your Flask app runs.  
  • Load Balancing: You might need to run many instances of your Flask app on different ports. This allows you to distribute incoming traffic, improving performance and resource use.  
  • Testing Environments: Port configuration is useful for creating separate testing environments. You can run development and production versions of your app on different ports. By isolating testing from production data and settings, we do this.  
  • Safety:  
  1. Security: Changing the default port can enhance security. Making it less predictable deters potential attackers.   
  2. Firewall Configuration: Port changes can simplify firewall configurations.   
  3. Isolation: Running your Flask app on a unique port can isolate it from other services. We do this to minimize the risk of unintended interactions that could be exploited.  
  • Customization: You have the flexibility to choose a port. That port aligns with app requirements or integrates with other services.   
  • Logging and Monitoring: Running different instances of your Flask app on different ports. This will allow you to separate logs. Making it easier to check and troubleshoot issues does this.  
  • Development and Testing: You can run many app versions using different ports. Various configurations do this. Aiding in debugging and feature testing does this process.  

In conclusion, using a flask change port function is a crucial step. You use that to enhance your brewing process. It streamlines the transfer of liquids, minimizes contamination risks, and ensures precise measurements.   

Fig: Preview of the output that you will get on running this code from your IDE.


In this solution we are using flask library in Python.


Follow the steps carefully to get the output easily.

  1. Download and Install the PyCharm Community Edition on your computer.
  2. Open the terminal and install the required libraries with the following commands.
  3. Create a new Python file on your IDE.
  4. Copy the snippet using the 'copy' button and paste it into your python file.
  5. Remove from line no: 11 to 19 and then save rest of the code.
  6. Run the current file to generate the output.

I hope you found this useful.

I found this code snippet by searching for 'How to change port in flask' in Kandi. You can try any such use case!

Environment Tested

I tested this solution in the following versions. Be mindful of changes when working with other versions.

  1. PyCharm Community Edition 2022.3.1
  2. The solution is created in Python 3.11.1 Version
  3. flask 2.2.5 Version

Using this solution, we can able to change port in flask in Python using pip with simple steps. This process also facilities an easy way to use, hassle-free method to create a hands-on working version of code which would help us to change port in flask in Python.

Dependent Library

flaskby pallets

Python doticonstar image 63300 doticonVersion:2.2.5doticon
License: Permissive (BSD-3-Clause)

The Python micro framework for building web applications.


            flaskby pallets

            Python doticon star image 63300 doticonVersion:2.2.5doticon License: Permissive (BSD-3-Clause)

            The Python micro framework for building web applications.

                      You can search for any dependent library on kandi like 'flask'.


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                      1. How can someone use a WSGI server to start a flask application on a different port?  

                      To start a Flask application on a different port using a WSGI server, you can follow these steps:  

                      • Install Flask: If you haven't already, install Flask using pip:  

                      pip install Flask  

                      • Create Your Flask App: Create a Flask application in a Python script. For example:  

                      from flask import Flask  

                      app = Flask(__name__)  

                      @app. route ('/') def hello_world(): return 'Hello, World!'  

                      if name == '__main__':  

                      • Choose a WSGI Server: You can use a WSGI server like Gunicorn, uWSGI, or mod_wsgi to run your Flask app. If your chosen server still needs installation, install it. For this example, we'll use Gunicorn:  

                      pip install gunicorn  

                      • Start the Flask App with the WSGI Server: Use the chosen WSGI server to start your Flask app on a different port. You can specify the port using the -b or -bind option.   

                      2. What is the framework for running Flask applications on many ports?  

                      To run Flask applications on many ports, use a combination of Flask and a web server like Gunicorn or uWSGI. Here is a high-level overview of the steps involved:  

                      • Install Flask: If you haven't already, install Flask in your project using pip.  
                      • Create Your Flask Application: Develop your Flask application as you would.  
                      • Choose a Web Server: Select a web server like Gunicorn or uWSGI to serve your Flask application. These servers can handle many ports.  
                      • Install the Web Server: Install the chosen web server. For Gunicorn, you can install it with pip.  
                      • Run the Flask App: Start your Flask application using the web server with the desired ports. 


                      3. How would a Python Developer set up Flask to run in two different ports?   

                      To set up a Flask app to run on two different ports, use the run method with the port parameter. It specifies the desired ports.   

                      Here's an example of how a Python developer can do this:   

                      from flask import Flask   

                      app = Flask(__name__)  

                      # Define your Flask routes and functions here  

                      if name == '__main__': # Run Flask on port 5000  

                      To run Flask on a different port (like 5001), use the command. In this example, the Flask app has two instances of the method. Specify each with a different port. Flask will create two separate instances of your app when you run this script. One on port 5000 and another on port 5001.  

                      4. What is the import path for setting up Flask applications with different ports?   

                      In Flask, you can set up applications with different ports. You can specify the port number when you run your Flask app using the method.   

                      Here's an example of how to do it:   

                      from flask import Flask  

                      app = Flask(__name__)  

                      @app.route('/') def hello_world(): return 'Hello, World!'  

                      if name == '__main__': # Run the Flask app on port 5000 # You can specify the desired port number here. The Flask app is set to run on port 5000 in this example. You can replace 5000 with any other port number you prefer. When you run this script, the Flask app will be accessible at http://localhost:5000 in your web browser.  

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