When using Python, a common error you may encounter is modulenotfounderror: no module named ‘flask’. This troubleshooting guide will help you overcome this problem.

How Does The Error “ModuleNotFoundError: No module named ‘flask’” Happen?

The ModuleNotFoundError occurs when you don’t install the module that you need to use. For example:

import flask

Output :

line 1, in <module>
import flask
ModuleNotFoundError: No module named 'flask'

What is Flask?

Flask is a microweb framework that is based on Python. It doesn’t require specific libraries or tools, so it is categorized as a microframework. It lacks form validation, database abstraction layers, or other components provided common functions by the third-party libraries.

If you want to know more about Flask, let’s access to this website. It’s helpful for you.

How To Solve This Problem?

Solution 1: Install the module ‘flask’

Because this Error occurs when the module you want to use does not appear in your Python environment. So you must install the module ‘flask’ to fix it.

First, you must install pip. Then, check if Python is installed.

Run the following command to test if python is installed or not.

python --version

Output:

Python 3.10.2

If Python doesn’t exist in your environment, download here.

Solution 2: Install pip for Windows

Let’s follow these steps to install pip for Windows:

Step 1: Download this file.

Step 2: Simply access Command Prompt, and quickly you can type “cmd” on the search bar.

Step 3: Enter this statement: “python get-pip.py”.

And you will see the result like this.

Collecting pip
  Using cached pip-22.2.2-py3-none-any.whl (2.0 MB)
Installing collected packages: pip
  Attempting uninstall: pip
    Found existing installation: pip 22.2.2
    Uninstalling pip-22.2.2:
      Successfully uninstalled pip-22.2.2
Successfully installed pip-22.2.2

Solution 3: Install pip for macOS 

Let’s follow these steps to install pip for macOS:

Step 1: Download this file.

Step 2: Now execute the downloaded file using the below command

python3 get-pip.py

Now you can install the module ‘flask’ by pip in Command Prompt.

pip install flask

Solution 4: Check if the module ‘flask’ is installed or not

To check if the module ‘flask’ is installed or not, let’s run the command below:

pip show flask 

Output :

Name: Flask
Version: 2.2.2
Summary: A simple framework for building complex web applications.
Home-page: https://palletsprojects.com/p/flask
Author: Armin Ronacher
Author-email: [email protected]
License: BSD-3-Clause
Location: c:\users\dell\appdata\local\programs\python\python310\lib\site-packages
Requires: click, itsdangerous, Jinja2, Werkzeug
Required-by:

Testing Flask

First, create a file called test.py and add the code below to the file:

from flask import Flask
app = Flask(__name__)
@app.route('/')
def example_code():C
    return 'How to solve ModuleNotFoundError: No module named flask Error'
if __name__ == '__main__':
    app.run()

Output: 

 * Serving Flask app 'test'
 * Debug mode: off
WARNING: This is a development server. Do not use it in a production deployment. Use a production WSGI server instead.
 * Running on http://127.0.0.1:5000
Press CTRL+C to quit

You can see the result at http://127.0.0.1:5000 .  

Summary

When using Python, a common error you may encounter is modulenotfounderror: no module named ‘flask’. The ModuleNotFoundError is raised when Python cannot locate an error. Normally, this error occurs because we forget to install a module or importing a module incorrectly. 

Now you’re ready to solve the ModuleNotFoundError Python error like an expert!

Read more

→ ModuleNotFoundError: No module named ‘click’