diff --git a/sugartrail/api.py b/sugartrail/api.py
index d2c7d41..48de8e8 100644
--- a/sugartrail/api.py
+++ b/sugartrail/api.py
@@ -2,7 +2,7 @@ import requests
 import time
 import os
 import functools
-from ratelimit import limits, RateLimitException, sleep_and_retry
+from ratelimit import limits, sleep_and_retry
 
 access_token = ""
 username = ""
diff --git a/sugartrail/base.py b/sugartrail/base.py
index 2bec71c..e59861b 100644
--- a/sugartrail/base.py
+++ b/sugartrail/base.py
@@ -2,9 +2,10 @@ import sugartrail
 import IPython
 import json
 import functools
-import pandas as pd
 
 class Network:
+    _unserialisable_attributes = ['hop', '_file', 'progress']
+
     """Class represents a network of connected companies, officers and
     addresses. Class contains methods to build network of user defined size from
     a single seed company, officer or address."""
@@ -142,7 +143,7 @@ class Network:
         return company_table
 
     @property
-    def address(self, value):
+    def address(self):
         """address property representing seed address."""
         return self._address
 
@@ -212,7 +213,7 @@ class Network:
 
     def save(self, filename, location='../assets/networks/'):
         """Saves network in JSON format to '../assets/networks/'."""
-        network_data = {k: v for k, v in self.__dict__.items() if k not in ['hop', 'file', 'progress']}
+        network_data = {k: v for k, v in self.__dict__.items() if k not in self._unserialisable_attributes}
         saved_network = json.dumps(network_data)
         f = open(location + f'{filename}', 'w')
         f.write(saved_network)
diff --git a/sugartrail/mapview.py b/sugartrail/mapview.py
index eab5d30..f1fbab1 100644
--- a/sugartrail/mapview.py
+++ b/sugartrail/mapview.py
@@ -1,8 +1,6 @@
 from ipywidgets import HTML, Widget, Layout, Output, VBox, HBox, Textarea
 from ipyleaflet import Map, Marker, MarkerCluster, AwesomeIcon, AntPath, Popup
-from datetime import datetime
 import functools
-import math
 
 def build_map(network, clear_widget=True):
     """Generates map and table for displaying paths for input network data."""
diff --git a/sugartrail/processing.py b/sugartrail/processing.py
index b100f14..2798dde 100644
--- a/sugartrail/processing.py
+++ b/sugartrail/processing.py
@@ -1,7 +1,5 @@
 from sugartrail import api
 import requests
-import pandas as pd
-import random
 import urllib
 import regex as re
 import collections
@@ -171,7 +169,6 @@ def build_address_history(company_id):
                         addresses.append(entry)
                     return addresses
                 else:
-                    address_history = []
                     entry = {}
                     for k, key in enumerate(["date_of_creation","date_of_cessation","registered_office_address"]):
                         if key in company_info:
@@ -184,7 +181,6 @@ def build_address_history(company_id):
                     entry["lon"] = ""
                     return [entry]
         else:
-            address_history = []
             entry = {}
             for k, key in enumerate(["date_of_creation","date_of_cessation","registered_office_address"]):
                 if key in company_info:
diff --git a/sugartrail/progress.py b/sugartrail/progress.py
index dc96676..d19c839 100644
--- a/sugartrail/progress.py
+++ b/sugartrail/progress.py
@@ -1,4 +1,3 @@
-import sugartrail
 import IPython
 
 class Progress:
diff --git a/test/test_base.py b/test/test_base.py
index a4416a9..3d33cb7 100644
--- a/test/test_base.py
+++ b/test/test_base.py
@@ -1,5 +1,4 @@
 import sugartrail
-import pytest
 import json
 
 # test 1: network initialised without auth and without arguments:
@@ -47,7 +46,7 @@ def test_file_init_without_auth():
     with open('./assets/networks/domain_corp_network.json') as f:
         network_json = json.load(f)
     for key in network.__dict__.keys():
-        if key not in ['hop', '_file', 'progress']:
+        if key not in sugartrail.base.Network._unserialisable_attributes:
             assert network.__dict__[key] == network_json[key]
 
 # test 5: network loads network from file without auth:
@@ -58,5 +57,5 @@ def test_file_load_without_auth():
     with open('./assets/networks/domain_corp_network.json') as f:
         network_json = json.load(f)
     for key in network.__dict__.keys():
-        if key not in ['hop', '_file', 'progress']:
+        if key not in sugartrail.base.Network._unserialisable_attributes:
             assert network.__dict__[key] == network_json[key]