A simple JSON only Alchemy API client for Python using the requests library.

client.py

import requests
import urllib


class AlchemyAPI(object):
    BASE_URL = 'https://access.alchemyapi.com'

    def __init__(self, api_key):
        self.api_key = api_key

    def keywords(self, text):
        results = self._call_endpoint('TextGetRankedKeywords', text)
        return [{'relevance': float(k['relevance']), 'text': k['text']} for k in
            results['keywords']]

    def sentiment(self, text):
        results = self._call_endpoint('TextGetTextSentiment', text)
        return (float(results['docSentiment']['score']),
            results['docSentiment']['type'])

    def _call_endpoint(self, name, text):
        endpoint = self._endpoint(name, text=text)
        resp = requests.get(endpoint)

        if resp.status_code != 200:
            raise Exception('API returned %s' % resp.status_code)

        if resp.json['status'] != 'OK':
            raise Exception('API status was not OK (%s)' % resp.json['status'])
        
        return resp.json

    def _endpoint(self, name, **kwargs):
        kwargs.update({
            'apikey': self.api_key,
            'outputMode': 'json',
        })

        return '%s/calls/text/%s?%s' % (self.BASE_URL, name, urllib.urlencode(kwargs))