How do I send multiple files in a single request using Requests?

Sending multiple files in a single request with the Python requests library is straightforward. You can achieve this by constructing a multipart/form-data request, which is the type of request that web forms typically use to upload files.

Here's how you can do it:

1. Import the requests library.
2. Construct the files dictionary, where each key is the name of the form field associated with the file upload. The value will be a tuple consisting of:
   • The filename (or None to use the filename of the file object).
   • The file object (or file-like object).
   • The content type (or None to use the default content type).
3. Make a POST request with the files parameter.

Below is an example of uploading two files in a single request using requests:

import requests

# Define the URL to the endpoint where you're sending the files
url = 'http://example.com/upload'

# Open the files in binary mode
with open('file1.txt', 'rb') as file1, open('file2.png', 'rb') as file2:
    # Create the files dictionary. The keys are the names of the form fields.
    files = {
        'text_file': ('custom_filename.txt', file1, 'text/plain'),
        'image_file': (file2.name, file2, 'image/png')
    }

    # Send the POST request with the files
    response = requests.post(url, files=files)

# Check if the request was successful and print the response
if response.ok:
    print('Upload successful.')
    print(response.text)
else:
    print('Upload failed.')

In this example, we are uploading a text file and a PNG image. The custom_filename.txt is the name we want to give to the uploaded file1.txt. For the image file, we are using the original filename.

Make sure that the keys in the files dictionary match the names expected by the server-side script or API that is handling the upload. If you're not sure what these should be, you might need to consult the API documentation or the HTML of the form that typically handles the upload.

Remember that when using with to open the files, they will be automatically closed after the with block. If you need to handle files manually, don't forget to close them after the request is made to avoid resource leaks.

This is the Python way to do it. If you need to send multiple files in a single request from a client-side JavaScript application, you'll use the FormData object and the fetch API or XMLHttpRequest. Here's an example using fetch:

// Create a new FormData object
let formData = new FormData();

// Append files to the FormData object
formData.append('text_file', new Blob(['File contents'], { type: 'text/plain' }), 'file1.txt');
formData.append('image_file', fileInputElement.files[0]);

// Define the URL to the endpoint where you're sending the files
const url = 'http://example.com/upload';

// Make the fetch request
fetch(url, {
  method: 'POST',
  body: formData
})
.then(response => {
  if (response.ok) {
    return response.text();
  } else {
    throw new Error('Upload failed.');
  }
})
.then(text => console.log('Upload successful:', text))
.catch(error => console.error('Error:', error));

In this JavaScript example, fileInputElement is a reference to an <input type="file"> HTML element from which you can get the files chosen by the user.

Both the Python and JavaScript examples demonstrate how to send multiple files in a single request to a server. The specific implementation on the server-side to handle these files will depend on the technology and framework you're using.