How to Download a File after POSTing Data Using FastAPI?
How to Download a File after POSTing Data using FastAPI?
When working with FastAPI and file handling, one common task is to enable users to download a file after submitting data through a POST request. This can be achieved by utilizing the FileResponse class and ensuring the proper configuration of headers and content type.
In the code provided below, we'll demonstrate how to set up a POST endpoint that processes data and returns an audio file (MP3) for download. We'll use the Form data type to capture user input and generate the audio file.
Option 1: Using a Separate Download Endpoint
In this approach, we'll create a separate endpoint for handling file downloads.
<code class="python">from fastapi import FastAPI, Request, Form, File, UploadFile
from fastapi.responses import FileResponse, HTMLResponse
from fastapi.templating import Jinja2Templates
from gtts import gTTS
app = FastAPI()
templates = Jinja2Templates(directory="templates")
def text_to_speech(language: str, text: str) -> str:
tts = gTTS(text=text, lang=language, slow=False)
filepath = "temp/welcome.mp3"
tts.save(filepath)
return f"Text to speech conversion successful to {filepath}"
@app.get("/")
def home(request: Request):
return templates.TemplateResponse("index.html", {"request": request})
@app.post("/text2speech")
def text2speech(request: Request, message: str = Form(...), language: str = Form(...)):
if message and language:
output = text_to_speech(language, message)
path = "temp/welcome.mp3"
filename = os.path.basename(path)
headers = {"Content-Disposition": f"attachment; filename={filename}"}
return FileResponse(path, headers=headers, media_type="audio/mp3")</code>The GET endpoint serves as the main page, while the POST endpoint handles user input and generates the audio file. The FileResponse takes care of setting the appropriate headers for file download.
In your template, you can add a link to trigger the file download:
<code class="html"><!DOCTYPE html>
<html>
<head>
<title>Download File</title>
</head>
<body>
<a href="{{ url_for('text2speech') }}">Download File</a>
</body>
</html></code>Option 2: In-Endpoint File Download
Alternatively, you can handle file download within the same endpoint that processes the data:
<code class="python">from fastapi import FastAPI, Request, Form
app = FastAPI()
def text_to_speech(language: str, text: str) -> str:
tts = gTTS(text=text, lang=language, slow=False)
filepath = "temp/welcome.mp3"
tts.save(filepath)
return f"Text to speech conversion successful to {filepath}"
@app.post("/text2speech")
def text2speech(request: Request, message: str = Form(...), language: str = Form(...)):
output = text_to_speech(language, message)
return {"filepath": filepath}</code>In your template, you can use JavaScript to trigger the file download using the filepath returned from the endpoint:
<code class="html"><script>
const filepath = "{{ filepath }}";
window.location.href = filepath;
</script></code>Handling Large Files
For files exceeding memory limits, you can use StreamingResponse:
<code class="python">from fastapi.responses import StreamingResponse
@app.post("/text2speech")
def text2speech(request: Request, message: str = Form(...), language: str = Form(...)):
...
def iterfile():
with open(filepath, "rb") as f:
yield from f
headers = {"Content-Disposition": f"attachment; filename={filename}"}
return StreamingResponse(iterfile(), headers=headers, media_type="audio/mp3")</code>Deleting Files After Download
To prevent disk space accumulation, it's good practice to delete files after they have been downloaded. Using BackgroundTasks, you can schedule the file deletion as a background task:
<code class="python">from fastapi import BackgroundTasks
@app.post("/text2speech")
def text2speech(request: Request, background_tasks: BackgroundTasks, ...):
...
background_tasks.add_task(os.remove, path=filepath)
return FileResponse(filepath, headers=headers, media_type="audio/mp3")</code>The above is the detailed content of How to Download a File after POSTing Data Using FastAPI?. For more information, please follow other related articles on the PHP Chinese website!
Hot AI Tools
Undresser.AI Undress
AI-powered app for creating realistic nude photos
AI Clothes Remover
Online AI tool for removing clothes from photos.
Undress AI Tool
Undress images for free
Clothoff.io
AI clothes remover
Video Face Swap
Swap faces in any video effortlessly with our completely free AI face swap tool!
Hot Article
Hot Tools
Notepad++7.3.1
Easy-to-use and free code editor
SublimeText3 Chinese version
Chinese version, very easy to use
Zend Studio 13.0.1
Powerful PHP integrated development environment
Dreamweaver CS6
Visual web development tools
SublimeText3 Mac version
God-level code editing software (SublimeText3)
Hot Topics
How to solve the permissions problem encountered when viewing Python version in Linux terminal?
Apr 01, 2025 pm 05:09 PM
Solution to permission issues when viewing Python version in Linux terminal When you try to view Python version in Linux terminal, enter python...
How to avoid being detected by the browser when using Fiddler Everywhere for man-in-the-middle reading?
Apr 02, 2025 am 07:15 AM
How to avoid being detected when using FiddlerEverywhere for man-in-the-middle readings When you use FiddlerEverywhere...
How to efficiently copy the entire column of one DataFrame into another DataFrame with different structures in Python?
Apr 01, 2025 pm 11:15 PM
When using Python's pandas library, how to copy whole columns between two DataFrames with different structures is a common problem. Suppose we have two Dats...
How does Uvicorn continuously listen for HTTP requests without serving_forever()?
Apr 01, 2025 pm 10:51 PM
How does Uvicorn continuously listen for HTTP requests? Uvicorn is a lightweight web server based on ASGI. One of its core functions is to listen for HTTP requests and proceed...
How to teach computer novice programming basics in project and problem-driven methods within 10 hours?
Apr 02, 2025 am 07:18 AM
How to teach computer novice programming basics within 10 hours? If you only have 10 hours to teach computer novice some programming knowledge, what would you choose to teach...
How to solve permission issues when using python --version command in Linux terminal?
Apr 02, 2025 am 06:36 AM
Using python in Linux terminal...
How to handle comma-separated list query parameters in FastAPI?
Apr 02, 2025 am 06:51 AM
Fastapi ...
How to get news data bypassing Investing.com's anti-crawler mechanism?
Apr 02, 2025 am 07:03 AM
Understanding the anti-crawling strategy of Investing.com Many people often try to crawl news data from Investing.com (https://cn.investing.com/news/latest-news)...
