diff --git a/.github/workflows/ci.yaml b/.github/workflows/tests.yaml
similarity index 80%
rename from .github/workflows/ci.yaml
rename to .github/workflows/tests.yaml
index 28191fe..2dc46ae 100644
--- a/.github/workflows/ci.yaml
+++ b/.github/workflows/tests.yaml
@@ -1,14 +1,14 @@
-name: Python data-flow
+name: Python data-flow Tests
 
-on: [push]
+on: [ push ]
 
 jobs:
-  build:
+  tests:
 
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        python-version: ["3.10", "3.11", "3.12"]
+        python-version: [ "3.10", "3.11", "3.12" ]
 
     steps:
       - uses: actions/checkout@v4
@@ -22,4 +22,6 @@ jobs:
       - name: Install modules
         run: pip install -r requirements.txt && pip install -r requirements.dev.txt
       - name: Tests
-        run: PYTHONPATH=. pytest --cov=data_flow --cov-report term
\ No newline at end of file
+        run: PYTHONPATH=. pytest --cov=data_flow --cov-report term
+      - name: Lint
+        run: flake8 data_flow/
\ No newline at end of file
diff --git a/Makefile b/Makefile
index b6f02c1..6a65b8b 100644
--- a/Makefile
+++ b/Makefile
@@ -8,7 +8,7 @@ pip::
 	venv/bin/pip install -r requirements.dev.txt
 
 tests::
-	PYTHONPATH=. venv/bin/pytest -rP tests/ -vvv --cov=data_flow --cov-report html --cov-report term
+	PYTHONPATH=. venv/bin/pytest --cov=data_flow --cov-report html --cov-report term -rP tests/ -vvv
 
 lint::
 	venv/bin/flake8 data_flow/
diff --git a/README.md b/README.md
index d03f271..0d28884 100644
--- a/README.md
+++ b/README.md
@@ -1,6 +1,6 @@
 # DataFlow
 
-![tests](https://github.com/mysiar-org/python-data-flow/actions/workflows/ci.yaml/badge.svg)
+![tests](https://github.com/mysiar-org/python-data-flow/actions/workflows/tests.yaml/badge.svg)
 [![Python 3.10](https://img.shields.io/badge/python-3.10-blue.svg)](https://www.python.org/downloads/release/python-3100/)
 [![Python 3.11](https://img.shields.io/badge/python-3.11-blue.svg)](https://www.python.org/downloads/release/python-3110/)
 [![Python 3.12](https://img.shields.io/badge/python-3.12-blue.svg)](https://www.python.org/downloads/release/python-3120/)
diff --git a/data_flow/data_flow.py b/data_flow/data_flow.py
index 84d304d..a699d55 100644
--- a/data_flow/data_flow.py
+++ b/data_flow/data_flow.py
@@ -3,6 +3,7 @@
 
 import fireducks.pandas as fd
 import pandas as pd
+import polars as pl
 from pyarrow import feather
 
 from data_flow.lib import FileType
@@ -44,18 +45,26 @@ def __del__(self):
             if not self.__in_memory:
                 delete_file(self.__filename)
 
-        def get_data_fireducks(self) -> fd.DataFrame:
+        def to_fireducks(self) -> fd.DataFrame:
             if self.__in_memory:
                 return self.__data
             else:
                 return df_from_tmp_filename(tmp_filename=self.__filename, file_type=self.__file_type)
 
-        def get_data_pandas(self) -> pd.DataFrame:
+        def to_pandas(self) -> pd.DataFrame:
             if self.__in_memory:
                 return self.__data.to_pandas()
             else:
                 return df_from_tmp_filename(tmp_filename=self.__filename, file_type=self.__file_type).to_pandas()
 
+        def to_polars(self) -> pl.DataFrame:
+            if self.__in_memory:
+                return pl.from_pandas(self.__data.to_pandas())
+            else:
+                return pl.from_pandas(
+                    df_from_tmp_filename(tmp_filename=self.__filename, file_type=self.__file_type).to_pandas()
+                )
+
         def from_csv(self, filename: str):
             if self.__in_memory:
                 self.__data = fd.read_csv(filename)
diff --git a/requirements.txt b/requirements.txt
index 5002da0..7d3d4f8 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,4 +1,5 @@
 fireducks
 tables
 pyarrow
-pandas
\ No newline at end of file
+pandas
+polars
\ No newline at end of file
diff --git a/tests/BaseTestCase.py b/tests/BaseTestCase.py
index db5501c..be9cf19 100644
--- a/tests/BaseTestCase.py
+++ b/tests/BaseTestCase.py
@@ -1,10 +1,12 @@
 import unittest
 from zipfile import ZipFile
 
+import pandas as pd
+
 
 class BaseTestCase(unittest.TestCase):
     def setUp(self):
-        zip = ZipFile(self.ZIP_FILE).extractall("./tests/data")
+        ZipFile(self.ZIP_FILE).extractall("./tests/data")
 
     ZIP_FILE = "./tests/data/annual-enterprise-survey-2023-financial-year-provisional.zip"
     CSV_FILE = "./tests/data/annual-enterprise-survey-2023-financial-year-provisional.csv"
@@ -13,3 +15,6 @@ def setUp(self):
     TEST_CSV_FILE = "/tmp/data-flow.csv"
     TEST_JSON_FILE = "/tmp/data-flow.json"
     TEST_HDF_FILE = "/tmp/data-flow.h5"
+
+    def assertPandasEqual(self, df1: pd.DataFrame, df2: pd.DataFrame):
+        self.assertTrue(df1.equals(df2), "Pandas DataFrames are not equal !")
diff --git a/tests/SequenceTestCase.py b/tests/SequenceTestCase.py
index 25f11e9..df44173 100644
--- a/tests/SequenceTestCase.py
+++ b/tests/SequenceTestCase.py
@@ -19,6 +19,7 @@ def _sequence(self, data: DataFlow.DataFrame) -> None:
                 "Variable_category",
             ]
         )
+
         self.assertEqual(3, len(data.columns()))
         self.assertListEqual(["Year", "Units", "Value"], data.columns())
 
diff --git a/tests/test_base_test_case.py b/tests/test_base_test_case.py
new file mode 100644
index 0000000..3bde473
--- /dev/null
+++ b/tests/test_base_test_case.py
@@ -0,0 +1,22 @@
+import unittest
+
+import pandas as pd
+
+from tests.BaseTestCase import BaseTestCase
+
+
+class BaseTestCaseTestCase(BaseTestCase):
+    def test_assert_pandas_equal(self):
+        df1 = pd.DataFrame({"col1": [1, 2, 3], "col2": [4, 5, 6]})
+        df2 = pd.DataFrame({"col1": [1, 2, 3], "col2": [4, 5, 6]})
+        df3 = pd.DataFrame({"Name": ["Tom", "nick", "krish", "jack"], "Age": [20, 21, 19, 18]})
+
+        self.assertPandasEqual(df1, df2)
+
+        with self.assertRaises(AssertionError) as context:
+            self.assertPandasEqual(df1, df3)
+        self.assertEqual(str(context.exception), "False is not true : Pandas DataFrames are not equal !")
+
+
+if __name__ == "__main__":
+    unittest.main()
diff --git a/tests/test_data_flow.py b/tests/test_data_flow.py
deleted file mode 100644
index 231b976..0000000
--- a/tests/test_data_flow.py
+++ /dev/null
@@ -1,83 +0,0 @@
-import os
-import unittest
-from typing import List
-
-from data_flow import DataFlow
-
-DATA_CSV = "/tmp/data_flow.csv"
-DATA_FEATHER = "/tmp/data_flow.feather"
-DATA_JSON = "/tmp/data_flow.json"
-DATA_PARQUET = "/tmp/data_parquet.parquet"
-DATA_HDF = "/tmp/data_flow.h5"
-
-
-def delete_file(filename: str) -> None:
-    if os.path.exists(filename):
-        os.remove(filename)
-
-
-def delete_files(files: List[str]) -> None:
-    for file in files:
-        delete_file(file)
-
-
-@unittest.skip
-class DataFlowTestCase(unittest.TestCase):
-    def setUp(self):
-        delete_files([DATA_CSV, DATA_FEATHER, DATA_JSON, DATA_PARQUET, DATA_HDF])
-
-        (
-            DataFlow()
-            .DataFrame()
-            .from_csv("./tests/data/annual-enterprise-survey-2023-financial-year-provisional.csv")
-            .to_csv(DATA_CSV)
-            .to_feather(DATA_FEATHER)
-            .to_json(DATA_JSON)
-            .to_parquet(DATA_PARQUET)
-            .to_hdf(DATA_HDF)
-        )
-
-    def test_csv(self):
-        data = DataFlow().DataFrame()
-        data.from_csv(DATA_CSV).stats()
-        data.del_columns(
-            [
-                "Industry_aggregation_NZSIOC",
-                "Industry_code_NZSIOC",
-                "Industry_name_NZSIOC",
-                "Industry_code_ANZSIC06",
-                "Variable_code",
-                "Variable_name",
-                "Variable_category",
-            ]
-        ).stats()
-
-        self.assertEqual(3, len(data.columns()))
-        self.assertListEqual(["Year", "Units", "Value"], data.columns())
-
-    @unittest.skip
-    def test_from_feather(self):
-        data = DataFlow().DataFrame()
-        data.from_feather(DATA_FEATHER).stats()
-
-    @unittest.skip
-    def test_from_json(self):
-        data = DataFlow().DataFrame()
-        data.from_json(DATA_JSON).stats()
-
-    @unittest.skip
-    def test_from_parquet(self):
-        data = DataFlow().DataFrame()
-        data.from_parquet(DATA_PARQUET).stats()
-
-    @unittest.skip
-    def test_from_hdf(self):
-        data = DataFlow().DataFrame()
-        data.from_hdf(DATA_HDF).stats()
-
-    def test(self):
-        DataFlow().DataFrame(in_memory=False).print()
-
-
-if __name__ == "__main__":
-    unittest.main()
diff --git a/tests/test_data_flow_csv.py b/tests/test_data_flow_csv.py
index c37e375..f8ce669 100644
--- a/tests/test_data_flow_csv.py
+++ b/tests/test_data_flow_csv.py
@@ -6,29 +6,33 @@
 
 class DataFlowCSVTestCase(SequenceTestCase):
     def test_memory(self):
-        data = (
+        df = (
             DataFlow().DataFrame().from_csv("./tests/data/annual-enterprise-survey-2023-financial-year-provisional.csv")
         )
-        self._sequence(data=data)
+        df.to_csv(self.TEST_CSV_FILE)
 
-        data.to_csv(self.TEST_CSV_FILE)
-        data.get_data_pandas().equals(DataFlow().DataFrame().from_csv(self.TEST_CSV_FILE).get_data_pandas())
+        self.assertPandasEqual(df.to_pandas(), DataFlow().DataFrame().from_csv(self.CSV_FILE).to_pandas())
+        self._sequence(data=df)
 
     def test_parquet(self):
-        data = (
+        df = (
             DataFlow()
             .DataFrame(in_memory=False)
             .from_csv("./tests/data/annual-enterprise-survey-2023-financial-year-provisional.csv")
         )
-        self._sequence(data=data)
+
+        self.assertPandasEqual(df.to_pandas(), DataFlow().DataFrame().from_csv(self.CSV_FILE).to_pandas())
+        self._sequence(data=df)
 
     def test_feather(self):
-        data = (
+        df = (
             DataFlow()
             .DataFrame(in_memory=False, file_type=FileType.feather)
             .from_csv("./tests/data/annual-enterprise-survey-2023-financial-year-provisional.csv")
         )
-        self._sequence(data=data)
+
+        self.assertPandasEqual(df.to_pandas(), DataFlow().DataFrame().from_csv(self.CSV_FILE).to_pandas())
+        self._sequence(data=df)
 
 
 if __name__ == "__main__":
diff --git a/tests/test_data_flow_feather.py b/tests/test_data_flow_feather.py
index 77b48b4..4a47ddf 100644
--- a/tests/test_data_flow_feather.py
+++ b/tests/test_data_flow_feather.py
@@ -12,17 +12,22 @@ def setUp(self):
         DataFlow().DataFrame().from_csv(self.CSV_FILE).to_feather(self.TEST_FEATHER_FILE)
 
     def test_memory(self):
-        data = DataFlow().DataFrame().from_feather(self.TEST_FEATHER_FILE)
-        self._sequence(data=data)
-        data.get_data_pandas().equals(DataFlow().DataFrame().from_csv(self.CSV_FILE).get_data_pandas())
+        df = DataFlow().DataFrame().from_feather(self.TEST_FEATHER_FILE)
+
+        self.assertPandasEqual(df.to_pandas(), DataFlow().DataFrame().from_csv(self.CSV_FILE).to_pandas())
+        self._sequence(data=df)
 
     def test_parquet(self):
-        data = DataFlow().DataFrame(in_memory=False).from_feather(self.TEST_FEATHER_FILE)
-        self._sequence(data=data)
+        df = DataFlow().DataFrame(in_memory=False).from_feather(self.TEST_FEATHER_FILE)
+
+        self.assertPandasEqual(df.to_pandas(), DataFlow().DataFrame().from_csv(self.CSV_FILE).to_pandas())
+        self._sequence(data=df)
 
     def test_feather(self):
-        data = DataFlow().DataFrame(in_memory=False, file_type=FileType.feather).from_feather(self.TEST_FEATHER_FILE)
-        self._sequence(data=data)
+        df = DataFlow().DataFrame(in_memory=False, file_type=FileType.feather).from_feather(self.TEST_FEATHER_FILE)
+
+        self.assertPandasEqual(df.to_pandas(), DataFlow().DataFrame().from_csv(self.CSV_FILE).to_pandas())
+        self._sequence(data=df)
 
 
 if __name__ == "__main__":
diff --git a/tests/test_data_flow_hdf.py b/tests/test_data_flow_hdf.py
index cdffefc..8bad9ce 100644
--- a/tests/test_data_flow_hdf.py
+++ b/tests/test_data_flow_hdf.py
@@ -12,17 +12,22 @@ def setUp(self):
         DataFlow().DataFrame().from_csv(self.CSV_FILE).to_hdf(self.TEST_HDF_FILE)
 
     def test_memory(self):
-        data = DataFlow().DataFrame().from_hdf(self.TEST_HDF_FILE)
-        self._sequence(data=data)
-        data.get_data_pandas().equals(DataFlow().DataFrame().from_csv(self.CSV_FILE).get_data_pandas())
+        df = DataFlow().DataFrame().from_hdf(self.TEST_HDF_FILE)
+
+        self.assertPandasEqual(df.to_pandas(), DataFlow().DataFrame().from_csv(self.CSV_FILE).to_pandas())
+        self._sequence(data=df)
 
     def test_parquet(self):
-        data = DataFlow().DataFrame(in_memory=False).from_hdf(self.TEST_HDF_FILE)
-        self._sequence(data=data)
+        df = DataFlow().DataFrame(in_memory=False).from_hdf(self.TEST_HDF_FILE)
+
+        self.assertPandasEqual(df.to_pandas(), DataFlow().DataFrame().from_csv(self.CSV_FILE).to_pandas())
+        self._sequence(data=df)
 
     def test_feather(self):
-        data = DataFlow().DataFrame(in_memory=False, file_type=FileType.feather).from_hdf(self.TEST_HDF_FILE)
-        self._sequence(data=data)
+        df = DataFlow().DataFrame(in_memory=False, file_type=FileType.feather).from_hdf(self.TEST_HDF_FILE)
+
+        self.assertPandasEqual(df.to_pandas(), DataFlow().DataFrame().from_csv(self.CSV_FILE).to_pandas())
+        self._sequence(data=df)
 
 
 if __name__ == "__main__":
diff --git a/tests/test_data_flow_json.py b/tests/test_data_flow_json.py
index b35f556..c5dfc71 100644
--- a/tests/test_data_flow_json.py
+++ b/tests/test_data_flow_json.py
@@ -12,17 +12,19 @@ def setUp(self):
         DataFlow().DataFrame().from_csv(self.CSV_FILE).to_json(self.TEST_JSON_FILE)
 
     def test_memory(self):
-        data = DataFlow().DataFrame().from_json(self.TEST_JSON_FILE)
-        self._sequence(data=data)
-        data.get_data_pandas().equals(DataFlow().DataFrame().from_csv(self.CSV_FILE).get_data_pandas())
+        df = DataFlow().DataFrame().from_json(self.TEST_JSON_FILE)
+        self.assertPandasEqual(df.to_pandas(), DataFlow().DataFrame().from_csv(self.CSV_FILE).to_pandas())
+        self._sequence(data=df)
 
     def test_parquet(self):
-        data = DataFlow().DataFrame(in_memory=False).from_json(self.TEST_JSON_FILE)
-        self._sequence(data=data)
+        df = DataFlow().DataFrame(in_memory=False).from_json(self.TEST_JSON_FILE)
+        self.assertPandasEqual(df.to_pandas(), DataFlow().DataFrame().from_csv(self.CSV_FILE).to_pandas())
+        self._sequence(data=df)
 
     def test_feather(self):
-        data = DataFlow().DataFrame(in_memory=False, file_type=FileType.feather).from_json(self.TEST_JSON_FILE)
-        self._sequence(data=data)
+        df = DataFlow().DataFrame(in_memory=False, file_type=FileType.feather).from_json(self.TEST_JSON_FILE)
+        self.assertPandasEqual(df.to_pandas(), DataFlow().DataFrame().from_csv(self.CSV_FILE).to_pandas())
+        self._sequence(data=df)
 
 
 if __name__ == "__main__":
diff --git a/tests/test_data_flow_parquet.py b/tests/test_data_flow_parquet.py
index 78a26cd..1b1dcee 100644
--- a/tests/test_data_flow_parquet.py
+++ b/tests/test_data_flow_parquet.py
@@ -12,17 +12,22 @@ def setUp(self):
         DataFlow().DataFrame().from_csv(self.CSV_FILE).to_parquet(self.TEST_PARQUET_FILE)
 
     def test_memory(self):
-        data = DataFlow().DataFrame().from_parquet(self.TEST_PARQUET_FILE)
-        self._sequence(data=data)
-        data.get_data_pandas().equals(DataFlow().DataFrame().from_csv(self.CSV_FILE).get_data_pandas())
+        df = DataFlow().DataFrame().from_parquet(self.TEST_PARQUET_FILE)
+
+        self.assertPandasEqual(df.to_pandas(), DataFlow().DataFrame().from_csv(self.CSV_FILE).to_pandas())
+        self._sequence(data=df)
 
     def test_parquet(self):
-        data = DataFlow().DataFrame(in_memory=False).from_parquet(self.TEST_PARQUET_FILE)
-        self._sequence(data=data)
+        df = DataFlow().DataFrame(in_memory=False).from_parquet(self.TEST_PARQUET_FILE)
+
+        self.assertPandasEqual(df.to_pandas(), DataFlow().DataFrame().from_csv(self.CSV_FILE).to_pandas())
+        self._sequence(data=df)
 
     def test_feather(self):
-        data = DataFlow().DataFrame(in_memory=False, file_type=FileType.feather).from_parquet(self.TEST_PARQUET_FILE)
-        self._sequence(data=data)
+        df = DataFlow().DataFrame(in_memory=False, file_type=FileType.feather).from_parquet(self.TEST_PARQUET_FILE)
+
+        self.assertPandasEqual(df.to_pandas(), DataFlow().DataFrame().from_csv(self.CSV_FILE).to_pandas())
+        self._sequence(data=df)
 
 
 if __name__ == "__main__":