[W.I.P.] URL Build Alternate Design

In order to improve code reuse, I completely redesigned the way that URLs are built.
I moved the make_url function (now renamed build_url) to the Client class. I thought this to be a better solution
as opposed to having the function implemented in every child class. A few changes still need to be made in order
to increase readability.

Author: taylorjdawson

etherscan/client.py

@@ -1,44 +1,81 @@
 import requests
 import json
-
+import collections
 
 #  Assume user puts his API key in the api_key.json file under variable name "key"
 class Client(object):
     dao_address = '0xbb9bc244d798123fde783fcc1c72d3bb8c189413'
-    URL_BASES = dict(
-        prefix='https://api.etherscan.io/',
-        module='api?module=',
-        action='&action=',
-        tag='&tag=',
-        offset='&offset=',
-        page='&page=',
-        sort='&sort=',
-        blocktype='&blocktype=',
-        key='&apikey=',
-        address='&address=',
-    )
 
-    def __init__(self, address, api_key='YourApiKeyToken'):
+    # Constants
+    PREFIX = 'https://api.etherscan.io/api?'
+    MODULE = 'module='
+    ACTION = '&action='
+    TOKEN_NAME = '&tokenname='
+    CONTRACT_ADDRESS = '&contractaddress='
+    ADDRESS = '&address='
+    OFFSET = '&offset='
+    PAGE = '&page='
+    SORT = '&sort='
+    BLOCK_TYPE = '&blocktype='
+    TO = '&to='
+    VALUE = '&value='
+    DATA = '&data='
+    POSITION = '&='
+    HEX = '&hex='
+    GAS_PRICE = '&gasPrice='
+    GAS = '&gas='
+    START_BLOCK = '&startblock='
+    END_BLOCK = '&endblock='
+    BLOCKNO = '&blockno='
+    TXHASH = '&txhash='
+    TAG = '&tag='
+    BOOLEAN = '&boolean='
+    INDEX = '&index='
+    API_KEY = '&apikey='
+
+    url_dict = {}
+
+    def __init__(self, address, api_key=''):
         self.http = requests.session()
-        self.url = ''
-        self.module = ''
-        self.action = ''
-        self.tag = ''
-        self.offset = ''
-        self.page = ''
-        self.sort = ''
-        self.blocktype = ''
+        self.url_dict = collections.OrderedDict(
+            {
+                self.MODULE: '',
+                self.ADDRESS: '',
+                self.OFFSET: '',
+                self.PAGE: '',
+                self.SORT: '',
+                self.BLOCK_TYPE: '',
+                self.TO: '',
+                self.VALUE: '',
+                self.DATA: '',
+                self.POSITION: '',
+                self.HEX: '',
+                self.GAS_PRICE: '',
+                self.GAS: '',
+                self.START_BLOCK: '',
+                self.END_BLOCK: '',
+                self.BLOCKNO: '',
+                self.TXHASH: '',
+                self.TAG: '',
+                self.BOOLEAN: '',
+                self.INDEX: '',
+                self.API_KEY: api_key,
+            })
 
-        self.API_KEY = str(api_key)
+        # self.url_dict[API_KEY] = str(api_key)
         self.check_and_get_api()
-        self.key = self.URL_BASES['key'] + self.API_KEY
+        # self.key = self.URL_BASES['key'] + self.API_KEY
+
         if (len(address) > 20) and (type(address) == list):
             print("Etherscan only takes 20 addresses at a time")
             quit()
         elif (type(address) == list) and (len(address) <= 20):
-            self.address = self.URL_BASES['address'] + ','.join(address)
+            self.url_dict[self.ADDRESS] = ','.join(address)
         else:
-            self.address = self.URL_BASES['address'] + address
+            self.url_dict[self.ADDRESS] = address
+
+    def build_url(self):
+        self.url = self.PREFIX + ''.join([k + v if v else '' for k, v in self.url_dict.items()])  # TODO: better naming
 
     def connect(self):
         # TODO: deal with "unknown exception" error
@@ -54,11 +91,11 @@ def connect(self):
                 print("Invalid Request")
                 exit()
         else:
-            print("problem with connection, status code: ", req.status_code)
+            print("Problem with connection, status code: ", req.status_code)
             exit()
 
     def check_and_get_api(self):
-        if self.API_KEY != 'YourApiKeyToken':
+        if self.url_dict[self.API_KEY]:  # Check if api_key is empty string
             pass
         else:
-            self.API_KEY = input('Please type your EtherScan.io API key: ')
+            self.url_dict[self.API_KEY] = input('Please type your EtherScan.io API key: ')