How to generate an oauth signature in PHP ( convert python to php ) -

i need convert python function php (oauth signature)

def generate_signature(method, url, data):         data['client_id'] = client_id         sorted_keys = sorted(data.keys())         message = '&'.join(["%s=%s" % (k, urllib.quote_plus(data[k])) k in sorted_keys])         message = "%s&%s&%s" % (method.upper(), urllib.quote_plus(url), message)         signature = hmac.new(client_secret, message.encode('utf-8'), hashlib.sha256).hexdigest()         return signature 

so far have

   private function buildbasestring($baseuri, $method, $params)      {         $return = array();         ksort($params);          foreach($params $key=>$value)         {             $return[] = "$key=" . $value;         }          return $method . "&" . rawurlencode($baseuri) . '&' . rawurlencode(implode('&', $return));      }  if (!is_null($getfield)) {     $getfields = str_replace('?', '', explode('&', $getfield));     foreach ($getfields $g)     {         $split = explode('=', $g);         $oauth[$split[0]] = $split[1];     } }  $base_info = $this->buildbasestring($url, $requestmethod, $oauth); $composite_key = rawurlencode($consumer_secret) . '&'; $oauth_signature = base64_encode(hash_hmac('sha1', $base_info, $composite_key, true)); return $oauth_signature; 

however reasons doesn't work . ?