Python client for CryptoCompare

1.first_framework_code.py

class Client:
    
    def coin_list(self):
        return False
    
    def coin_snapshot_full_by_id(self, coin_id):
        return False
      
    def coin_snapshot(self, fsym, tsym):
        return False

2.second_real_code.py

import json
import urllib2


class Client:
    
    def coin_list(self):
        
        url = 'https://www.cryptocompare.com/api/data/coinlist/'

        print('Calling URL - ' + url)
    
        json_response = json.load(urllib2.urlopen(url))
        
        if 'Response' in json_response and json_response["Response"] == 'Error':
            raise ValueError("API Error - {} !".format(json_response['Message']))
        else:
            return json_response
        
    def coin_snapshot_full_by_id(self, coin_id):
        
        url = 'https://www.cryptocompare.com/api/data/coinsnapshotfullbyid/?id=' + coin_id

        print('Calling URL - ' + url)
    
        json_response = json.load(urllib2.urlopen(url))
        
        if 'Response' in json_response and json_response["Response"] == 'Error':
            raise ValueError("API Error - {} !".format(json_response['Message']))
        else:
            return json_response
      
    def coin_snapshot(self, fsym, tsym):
        
        url = 'https://www.cryptocompare.com/api/data/coinsnapshot/' + '?fsym='+fsym+'&tsym='+tsym

        print('Calling URL - ' + url)
    
        json_response = json.load(urllib2.urlopen(url))
        
        if 'Response' in json_response and json_response["Response"] == 'Error':
            raise ValueError("API Error - {} !".format(json_response['Message']))
        else:
            return json_response

3.third_refactoring_code.py

import json
import urllib2


class Client:

    
    COIN_LIST_URL = 'https://www.cryptocompare.com/api/data/coinlist/'
    COIN_SNAPSHOT_FULL_BY_ID_URL = 'https://www.cryptocompare.com/api/data/coinsnapshotfullbyid/?id='
    COIN_SNAPSHOT_URL  = 'https://www.cryptocompare.com/api/data/coinsnapshot/'
    

    def coin_list(self):
        
        return self._fetch_data(self.COIN_LIST_URL)

        
    def coin_snapshot_full_by_id(self, coin_id):
        
        if(coin_id == None or coin_id == ''):
            raise ValueError('coin_id cannot be empty!')

        return self._fetch_data(self.COIN_SNAPSHOT_FULL_BY_ID_URL+str(coin_id))
      
    
    def coin_snapshot(self, fsym, tsym):

        if(fsym == None or fsym == ''):
            raise ValueError('fsym cannot be empty!')

        if(tsym == None or tsym == ''):
            raise ValueError('tsym cannot be empty!')
        
        return self._fetch_data(self.COIN_SNAPSHOT_URL+'?fsym='+fsym+'&tsym='+tsym)


    def _fetch_data(self, url):

        print('Calling URL - ' + url)
        
        json_response = json.load(urllib2.urlopen(url))
        
        if 'Response' in json_response and json_response["Response"] == 'Error':
            raise ValueError("API Error - {} !".format(json_response['Message']))
        else:
            return json_response

4.fourth_design_refactoring.py

class Client:
    
    COIN_LIST_URL = 'https://www.cryptocompare.com/api/data/coinlist/'
    COIN_SNAPSHOT_FULL_BY_ID_URL = 'https://www.cryptocompare.com/api/data/coinsnapshotfullbyid/?id='
    COIN_SNAPSHOT_URL  = 'https://www.cryptocompare.com/api/data/coinsnapshot/'

    PRICE_URL = 'https://min-api.cryptocompare.com/data/price'
    PRICE_MULTI_URL = 'https://min-api.cryptocompare.com/data/pricemulti'
    PRICE_MULTI_FULL_URL = 'https://min-api.cryptocompare.com/data/pricemultifull'
    PRICE_HISTORICAL_URL = 'https://min-api.cryptocompare.com/data/pricehistorical'

    GENERATE_AVG_URL = 'https://min-api.cryptocompare.com/data/generateAvg'
    DAY_AVG_URL = 'https://min-api.cryptocompare.com/data/dayAvg'

    SUBS_WATCH_LIST_URL = 'https://min-api.cryptocompare.com/data/subsWatchlist'
    SUBS_URL = 'https://min-api.cryptocompare.com/data/subs'

    ALL_EXCHANGES_URL = 'https://min-api.cryptocompare.com/data/all/exchanges'
    TOP_EXCHANGES_URL = 'https://min-api.cryptocompare.com/data/top/exchanges'
    TOP_VOLUMES_URL = 'https://min-api.cryptocompare.com/data/top/volumes'
    TOP_PAIRS_URL = 'https://min-api.cryptocompare.com/data/top/pairs'

    HISTO_DAY_URL = 'https://min-api.cryptocompare.com/data/histoday'
    HISTO_HOUR_URL = 'https://min-api.cryptocompare.com/data/histohour'
    HISTO_MINUTE_URL = 'https://min-api.cryptocompare.com/data/histominute'

    SOCIAL_STATS_URL = 'https://www.cryptocompare.com/api/data/socialstats?id='

    MINING_CONTRACTS_URL = 'https://www.cryptocompare.com/api/data/miningcontracts/'
    MINING_EQUIPMENT_URL = 'https://www.cryptocompare.com/api/data/miningequipment/'

    #1. Grouped related API methods together, and moved them into a module.
    #2. Include all the module methods inside the class so that the module methods becomes class instance methods.
    
    # This way, methods are available to use at runtime, but the code is separated and more readable/maintainable.
    
    from .apis.coin import coin_list, coin_snapshot_full_by_id, coin_snapshot
    from .apis.price import price, price_multi, price_multifull, price_historical
    from .apis.average import generate_avg, day_avg
    from .apis.subs import subs_watchlist, subs
    from .apis.top import top_exchanges, top_volumes, top_pairs
    from .apis.histo import histo_day, histo_hour, histo_minute
    from .apis.mining import mining_contracts, mining_equipment
    from .apis.uncategorized import all_exchanges, social_stats

    from .apis.helper import _is_params_valid, _fetch_data, _get_querystring