only import polars in typecheck

setup.cfg

@@ -55,6 +55,7 @@ dev =
     pytest-cov
     pytest-snapshot
     vetiver[typecheck]
+    polars
 
 docs =
     quartodoc

vetiver/prototype.py

@@ -8,12 +8,18 @@
 
 import pandas as pd
 import numpy as np
-import polars as pl
 import pydantic
+import typing
 from pydantic import Field
 from warnings import warn
 from .types import create_prototype
 
+if typing.TYPE_CHECKING:
+    try:
+        import polars as pl
+    except ImportError:
+        pl = None
+
 
 class InvalidPTypeError(Exception):
     """