diff --git a/co2calculator/data_handlers.py b/co2calculator/data_handlers.py
index a698e0d..ec87472 100644
--- a/co2calculator/data_handlers.py
+++ b/co2calculator/data_handlers.py
@@ -1,7 +1,7 @@
 #!/usr/bin/env python
 # -*- coding: utf-8 -*-
-"""Reader class to retrieve co2 factors from database"""
-import warnings
+"""Data handler class to handle and validate emission factors from csv file"""
+
 from pathlib import Path
 import pandas as pd
 from .exceptions import ConversionFactorNotFound
@@ -28,7 +28,7 @@ def get(self, parameters: dict):
         selected_factors = self.emission_factors
 
         for k, v in parameters.items():
-            # shortterm hack to make it work until co2 factors are updated
+            # TODO: shortterm hack to make it work until occupancy is removed from emission factors
             if not isinstance(v, int):
                 v = str(v.value)
             if v is None or k not in self.column_names:
diff --git a/co2calculator/exceptions.py b/co2calculator/exceptions.py
index e097960..752ff91 100644
--- a/co2calculator/exceptions.py
+++ b/co2calculator/exceptions.py
@@ -1,6 +1,6 @@
 #!/usr/bin/env python
 # -*- coding: utf-8 -*-
-"""__description__"""
+"""Exceptions for the co2calculator package"""
 
 __author__ = "Christina Ludwig, GIScience Research Group, Heidelberg University"
 __email__ = "christina.ludwig@uni-heidelberg.de"
diff --git a/co2calculator/parameters.py b/co2calculator/parameters.py
index 4618b77..8ba3a7e 100644
--- a/co2calculator/parameters.py
+++ b/co2calculator/parameters.py
@@ -1,8 +1,8 @@
 #!/usr/bin/env python
 # -*- coding: utf-8 -*-
-"""__description__"""
+"""Base classes to handle and validate parameters for emission calculations"""
 
-from pydantic import BaseModel, validator, root_validator
+from pydantic import BaseModel, validator
 from .constants import (
     TransportationMode,
     Size,