Inconsistent behavior when converting cURL multipart/form-data request to Python requests

Author: COCONUTwwaterCreated Apr 21, 2025Updated Sep 2, 2025

Labelsincorrect output

Issue Description

When converting a cURL request with multipart/form-data to Python requests, the request fails to match the original cURL behavior, while Postman's conversion works correctly.

Steps to Reproduce

Original cURL request:

bash

curl 'https://example.com/' \
  -H 'content-type: multipart/form-data; boundary=----WebKitFormBoundaryaaaaa' \
  --data-raw $'------WebKitFormBoundaryaaaaa\r\nContent-Disposition: form-data; name="time_type"\r\n\r\nBILL_TIME\r\n------WebKitFormBoundaryaaaaa\r\nContent-Disposition: form-data; name="start_time"\r\n\r\n1735660800\r\n------WebKitFormBoundaryaaaaa\r\nContent-Disposition: form-data; name="end_time"\r\n\r\n1745164799\r\n------WebKitFormBoundaryaaaaa--\r\n'

Python requests attempt (not working):

python

import requests

headers = {
    'content-type': 'multipart/form-data; boundary=----WebKitFormBoundaryaaaaa',
}

files = {
    'time_type': (None, 'BILL_TIME'),
    'start_time': (None, '1735660800'),
    'end_time': (None, '1745164799'),
}

response = requests.post('https://example.com/', headers=headers, files=files)

Postman's conversion (working):

python

import requests

url = "https://example.com/"
payload = {
    'time_type': 'BILL_TIME',
    'start_time': '1735660800',
    'end_time': '1745164799'
}
files = []
headers = {
    'accept': 'application/json, text/plain, */*'
}

response = requests.request("POST", url, headers=headers, data=payload, files=files)

Expected Behavior

The Python requests library should generate the same multipart/form-data request as the original cURL command.

Actual Behavior

The Python requests library generates a different multipart/form-data structure, causing the request to fail.

Source: curlconverter/curlconverter

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