title: How to send form-data using python requests?
body: <p>I'm trying to send a POST request using python 3 and the requests library. When I use postman I'm obtaining the result that I'm expecting, so I copy the code generated by Postman, and in that way it is working.</p>
  
  <p>This is the code generated by postman code:</p>
  
  <pre><code>import requests
  
  payload = "name=\"claveElector\"\r\n\r\nABCDEF01234567H400\r\nname=\"numeroEmision\"\r\n\r\n01\r\nname=\"ocr\"\r\n\r\n4158093946570\r\nname=\"g-recaptcha-response\"\r\n\r\nsome-captcha\r\nname=\"modelo\"\r\n\r\na"
  
  url = "https://listanominal.ine.mx/scpln/resultado.html"
  
  payload = "------WebKitFormBoundary7MA4YWxkTrZu0gW\r\nContent-Disposition: form-data; name=\"claveElector\"\r\n\r\nTPRSJC95010209H400\r\n------WebKitFormBoundary7MA4YWxkTrZu0gW\r\nContent-Disposition: form-data; name=\"numeroEmision\"\r\n\r\n01\r\n------WebKitFormBoundary7MA4YWxkTrZu0gW\r\nContent-Disposition: form-data; name=\"ocr\"\r\n\r\n4158093946570\r\n------WebKitFormBoundary7MA4YWxkTrZu0gW\r\nContent-Disposition: form-data; name=\"g-recaptcha-response\"\r\n\r\nsome-re-captcha\r\n------WebKitFormBoundary7MA4YWxkTrZu0gW\r\nContent-Disposition: form-data; name=\"modelo\"\r\n\r\na\r\n------WebKitFormBoundary7MA4YWxkTrZu0gW--"
  headers = {
      'content-type': "multipart/form-data; boundary=----WebKitFormBoundary7MA4YWxkTrZu0gW",
  }
  
  response = requests.request("POST", url, data=payload, headers=headers)
  
  print(response.text)
  </code></pre>
  
  <p>To be more clear in the part of why is not working is the difference that exists in both results. </p>
  
  <p><a href="https://codepen.io/Jacktapiaro101/pen/EBmQMQ" rel="noreferrer">With the postman code i got this</a></p>
  
  <p>That code is generated with the following data:
  <a href="https://i.stack.imgur.com/2FH2j.jpg" rel="noreferrer"><img src="https://i.stack.imgur.com/2FH2j.jpg" alt="That code is generated with the following data"></a></p>
  
  <p>So I tried to do the same using my own code, I've tried to send the data in the file part, and in the data part but is not working. Reading other StackOverflow questions, they suggest to use the MultipartEncoder that is part of the Requests Toolbelt library.</p>
  
  <p>So my implementation ended up like this:</p>
  
  <pre><code>import requests
  from requests_toolbelt.multipart.encoder import MultipartEncoder
  
  clave_elector = "ABCDEF01234567H400"
  numero_emision = "01"
  ocr = "1234567846570"
  modelo = "a"
  
  params = {
      "claveElector": clave_elector,
      "numeroEmision": numero_emision,
      "ocr": ocr,
      "modelo": modelo,
      "g-recaptcha-response": ''
  }
  
  data = MultipartEncoder(fields = params)
  
  headers = {
      'Content-type': data.content_type
  }
  response = requests.post(
      'https://listanominal.ine.mx/scpln/resultado.html',
      data = data,
      headers = headers
  )
  print(response.text)
  </code></pre>
  
  <p><a href="https://codepen.io/Jacktapiaro101/pen/orWEOa" rel="noreferrer">With the custom code I got the following</a></p>
  
  <p>If you try both codes, you can see how the results are different. And I'm interested in the first one, the one that is got with the code that was generated by Postman.</p>
  
  <p>I don't know why my code is not working, what I am doing wrong?
  What I'm trying to say is that somehow with my code the request is not being send properly so the website is not able to read it.</p>