create the code for a python http api using the sanic library application to allow files to be requested and streamed from a directory. in python

You can create an HTTP API using Sanic WebSockets library in Python 3 that allows files to be requested and streamed from a specific directory. Here is the sample code to achieve this:

main.py
from sanic import Sanic
from sanic.response import file

app = Sanic()

@app.route("/download/<filename>")
async def download(request, filename):
    # Define the directory path where the files exist
    directory = "/path/to/files"

    # Send file with filename matching route parameter
    return await file(location=f"{directory}/{filename}", mime_type='application/octet-stream')

if __name__ == '__main__':
    app.run(host='0.0.0.0', port=8000)
452 chars
16 lines

In this code, a new Sanic app is initialized and a function named download() is defined with <filename> as a parameter in the route "/download/". This function takes in a filename parameter, reads the file from the specified directory and returns the file as a response. The response is based on the file's MIME type, which is set to 'application/octet-stream' enabling it to be downloaded like files without defined MIME types.

To test this API use the curl command in your terminal:

$ curl http://localhost:8000/download/sample_file.txt -o sample_file.txt
73 chars
2 lines

This will download the file locally in the directory from which the command was executed.