Python-3 Request Parameter Encoding Error

I have been working on a django project based upon Python 3. I am trying to incorporate captcha. I choosed django-recaptcha but unfortunately the package is not available for pytho

Solution 1:

Alright I will answer this myself :P.

Taking hints from an example at python's official documentation, I excluded data from Request and separately passed request and data to urlopen(). Below is the updated snippet -

params = urllib.parse.urlencode({
        'privatekey': encode_if_necessary(private_key),
        'remoteip':  encode_if_necessary(remoteip),
        'challenge':  encode_if_necessary(recaptcha_challenge_field),
        'response':  encode_if_necessary(recaptcha_response_field),
        })

if use_ssl:
    verify_url = "https://%s/recaptcha/api/verify" % VERIFY_SERVER
else:
    verify_url = "http://%s/recaptcha/api/verify" % VERIFY_SERVER
# do not add data to Request instead pass it separately to urlopen()
data = params.encode('utf-8')
request = urllib.request.Request(verify_url)
request.add_header("Content-type","application/x-www-form-urlencoded")
request.add_header("User-agent", "reCAPTCHA Python")

httpresp = urllib.request.urlopen(request, data)

Despite of solving the problem I still do not know why the code generated by 2to3.py did not work. According to the documentation it should have worked.

Solution 2:

You guessed correctly, you need to encode the data, but not the way you did it.

As @Sheena wrote in this SO answer, you need 2 steps to encode you data:

data = urllib.parse.urlencode(values)
binary_data = data.encode('utf-8')
req = urllib.request.Request(url, binary_data)

And do not encore the url.