diff --git a/.flake8 b/.flake8
index 7da1f96..41a0a51 100644
--- a/.flake8
+++ b/.flake8
@@ -1,2 +1,3 @@
 [flake8]
 max-line-length = 100
+ignore = F821
diff --git a/src/model.py b/src/model.py
index 688be10..92636e4 100644
--- a/src/model.py
+++ b/src/model.py
@@ -216,7 +216,8 @@ def remove_net_zero_countries(self) -> None:
 
         # print the number of countries removed
         print(
-            f"Removed {shape_before - self.trade_matrix.shape[0]} countries with no trade or production."
+            f"Removed {shape_before - self.trade_matrix.shape[0]} "
+            f"countries with no trade or production."
         )
 
     def prebalance(self, precision=10**-3) -> None:
diff --git a/src/preprocessing.py b/src/preprocessing.py
index ee97b4b..5b35f26 100644
--- a/src/preprocessing.py
+++ b/src/preprocessing.py
@@ -74,11 +74,11 @@ def serialise_faostat_bulk(faostat_zip: str) -> None:
     """
     data = read_faostat_bulk(faostat_zip)
     print("Starting to convert zip to pickle")
-    data.to_pickle(
-        f"data{os.sep}temp_files{os.sep}{faostat_zip[faostat_zip.rfind('/') + 1:].replace(
-            'zip', 'pkl'
-        )}"
-    )
+    base_path = "data" + os.sep + "temp_files" + os.sep
+    formatted_filename = faostat_zip[faostat_zip.rfind('/') + 1:].replace('zip', 'pkl')
+    full_path = f"{base_path}{formatted_filename}"
+
+    data.to_pickle(full_path)
     print("Finished converting zip to pickle")
     return None
 
diff --git a/tests/test_model.py b/tests/test_model.py
index cbfdabd..54b603a 100644
--- a/tests/test_model.py
+++ b/tests/test_model.py
@@ -3,7 +3,6 @@
 import os
 import numpy as np
 from src.preprocessing import rename_countries
-import country_converter as coco
 
 
 def loading(region):