Flask python download file

This UI contains only one link for downloading a file from the server. Clicking on the link will ask user to save the file in a chosen location.

The file type could be anything. As you see I have tested with four types of files. I hope this example will work with other file types as well. Now create a download. Notice in the above template file I am using Flask EL Expression language to evaluate the link endpoint. Now navigate to the project root directory from command line tool and execute the command python main.

If you want to change the port then you can change the line app. Connect and share knowledge within a single location that is structured and easy to search. My goal is to be able to download a file on a web browser when the user access to a web service on my Flask-base Python server. Stack Overflow for Teams — Collaborate and share knowledge with a private group.

Create a free Team What is Teams? Collectives on Stack Overflow. Learn more. Download a file from a Flask-based Python server Ask Question. Asked 5 years, 5 months ago. Active 2 years, 6 months ago. Viewed 34k times. So I wrote the following code: app. After that, create a file with the name upload. After creating the HTML template for the file uploader, now, in the main directory, create a file with the name app. The app. Copy the following code into the app.

In the above code, we first imported the required modules to our code. After importing the required modules, we initialize the Flask app by calling the Flask constructor. Next, we use python decorators to define the routes for our Flask app and serve the HTML template that we created. Next, we use python decorators to accept the post request for the file and save the file. You can run the above code by just typing python app.

We will see something as shown in the below image while running the above code. Upload a sample file by choosing a file and clicking the submit button. After submitting the file, we will get a message showing that the file has been successfully uploaded.

We can check the file in the server by visiting the root directory. We created a file uploader that saves the uploaded file in the root directory. We can also configure the directory for saving the file by configuring the app. At first, the uploaded file is saved into a temporary location, and then it moves to the final location.

The following code shows how to configure the upload directory. In the above code, we use the OS module of python to create a directory and saves every uploaded file to the created directory. If we restart the server and upload a file to the server, the file will be uploaded to the created directory instead of the root directory.

We can also configure the maximum upload size of the file. This is important because if the file is too large for the server, then the site may crash. So, we need to always limit the upload size of the file according to our server. To configure the maximum file size, we need to set the app. For example, if we want to limit the maximum size of the file to 1 Mb, we need to add the following line of code in our program.

After setting the maximum file size of the file in our python program, if we upload a file having a size of more than 1 Mb, then we will get the error as shown in the below image. While building a file uploader using Flask, we can also configure the file extensions that we want to upload.

To configure the allowed file extensions, we need to create a list of allowed extensions and check the uploaded file extension in the list. Jul 27, Jul 15, Jun 18, May 28, May 27, Download the file for your platform. If you're not sure which to choose, learn more about installing packages. Warning Some features may not work without JavaScript. Please try enabling it if you encounter problems.

Search PyPI Search. Flask 2. Latest version Released: Oct 4, A simple framework for building complex web applications. Navigation Project description Release history Download files. Maintainers davidism ThiefMaster. A Simple Example save this as app.