Add polars

https://www.pola.rs/

This one's well good, and is growing in popularity

Author: MarcoGorelli

Dockerfile.tmpl

@@ -190,6 +190,7 @@ RUN pip install pysal \
         seaborn python-dateutil dask python-igraph \
         pyyaml joblib husl geopy mne pyshp \
         pandas \
+        polars \
         flax && \
     # Install h2o from source.
     # Use `conda install -c h2oai h2o` once Python 3.7 version is released to conda.

tests/test_polars.py

@@ -0,0 +1,10 @@
+import unittest
+
+import polars as pl
+
+class TestPolars(unittest.TestCase):    
+    def test_read_csv(self):
+        data = pl.read_csv("/input/tests/data/train.csv")
+
+        self.assertEqual(100, len(data))
+