How to sign up to a website with python 3? - forms

Question

I would like to build a simple automated signer up for a website of mine.
I tried with this:
import requests
url = "http://pountex.altervista.org/registrati/"
payload = { "user": "a",
"email": "a#a.com",
"passw1": "a",
"passw2": "a" }
r = requests.post(url, data=payload)
print (r.text)
But nothing happends. The comment doesn't being created.
This is the html part of the comments form:
<input class="text-input default_field_username" name="username" maxlength="70" id="username" value="" type="text">
<input class="text-input default_field_email" name="email" maxlength="70" id="email" value="" type="email">
<input class="text-input" name="passw1" maxlength="70" id="passw1" value="" autocomplete="off" type="password">
<input class="text-input" name="passw2" maxlength="70" id="passw2" value="" autocomplete="off" type="password">
<input name="register" id="register" class="submit button" value="Registrati " type="submit">

Answer 1

#nander-speerstra thanks for your links, but the real problems was the http request. I've always sended:
payload = { "user": "a",
"email": "a#a.com",
"passw1": "a",
"passw2": "a" }
But after an analysis of http post request, i realized the there were these options:
Content-Disposition: form-data; name="username"
a
Content-Disposition: form-data; name="email"
a#a.com
Content-Disposition: form-data; name="passw1"
a
Content-Disposition: form-data; name="passw2"
a
Content-Disposition: form-data; name="register"
Registrati
Content-Disposition: form-data; name="action"
register
Content-Disposition: form-data; name="form_name"
unspecified
Content-Disposition: form-data; name="register_nonce_field"
5d5162e9e1
Content-Disposition: form-data; name="_wp_http_referer"
/registrati/
So the final script is:
import requests
url = "http://pountex.altervista.org/registrati/"
payload = { "username":"a",
"email":"a#a.com",
"passw1":"a",
"passw2":"a",
"register":"Registrati ",
"action":"register",
"form_name":"unspecified",
"register_nonce_field":"59cf20fe78",
"_wp_http_referer":"/registrati/?doing_wp_cron=1470266089.5451300144195556640625"
}
r = requests.post(url, params=payload)