Add expression tests (#1894)

py-polars/polars/internals/construction.py

@@ -69,7 +69,7 @@ def numpy_to_pyseries(
     """
     Construct a PySeries from a numpy array.
     """
-    if not values.data.contiguous:
+    if not values.flags["C_CONTIGUOUS"]:
         values = np.array(values)
 
     if len(values.shape) == 1:

py-polars/polars/internals/expr.py

@@ -56,12 +56,7 @@ def _from_pyexpr(pyexpr: "PyExpr") -> "Expr":
         return self
 
     def __to_pyexpr(self, other: Any) -> "PyExpr":
-        if isinstance(other, PyExpr):
-            return other
-        elif isinstance(other, Expr):
-            return other._pyexpr
-        else:
-            return pli.lit(other)._pyexpr
+        return self.__to_expr(other)._pyexpr
 
     def __to_expr(self, other: Any) -> "Expr":
         if isinstance(other, Expr):
@@ -185,16 +180,13 @@ def __array_ufunc__(
         else:
             dtype = None  # type: ignore
 
-        args = []
-        for inp in inputs:
-            if not isinstance(inp, Expr):
-                args.append(inp)
+        args = [inp for inp in inputs if not isinstance(inp, Expr)]
 
         def function(s: "pli.Series") -> "pli.Series":
-            return ufunc(s, *args, **kwargs)
+            return ufunc(s, *args, **kwargs)  # pragma: no cover
 
         if "dtype" in kwargs:
-            return self.map(function, return_dtype=kwargs["dtype"])
+            dtype = kwargs["dtype"]
 
         return self.map(function, return_dtype=dtype)
 
@@ -741,7 +733,9 @@ def sort_by(
 
         return wrap_expr(self._pyexpr.sort_by(by, reverse))
 
-    def take(self, index: Union[tp.List[int], "Expr", "pli.Series"]) -> "Expr":
+    def take(
+        self, index: Union[tp.List[int], "Expr", "pli.Series", np.ndarray]
+    ) -> "Expr":
         """
         Take values by index.
 

py-polars/tests/test_datelike.py

@@ -1,5 +1,6 @@
 from datetime import date, datetime, timedelta
 
+import numpy as np
 import pyarrow as pa
 import pytest
 
@@ -153,6 +154,14 @@ def test_to_python_datetime() -> None:
     )
 
 
+def test_from_numpy() -> None:
+    # numpy support is limited; will be stored as object
+    x = np.asarray(range(100_000, 200_000, 10_000), dtype="datetime64[s]")
+    s = pl.Series(x)
+    assert s[0] == x[0]
+    assert len(s) == 10
+
+
 def test_datetime_consistency() -> None:
     # dt = datetime(2021, 1, 1, 10, 30, 45, 123456)
     dt = datetime(2021, 1, 1, 10, 30, 45, 123000)

py-polars/tests/test_exprs.py

@@ -10,7 +10,13 @@ def test_horizontal_agg(fruits_cars: pl.DataFrame) -> None:
     assert out[:, 0].to_list() == [1, 2, 3, 2, 1]
 
 
-def test_prefix(fruits_cars: pl.DataFrame) -> None:
+def test_suffix(fruits_cars: pl.DataFrame) -> None:
     df = fruits_cars
     out = df.select([pl.all().suffix("_reverse")])
     assert out.columns == ["A_reverse", "fruits_reverse", "B_reverse", "cars_reverse"]
+
+
+def test_prefix(fruits_cars: pl.DataFrame) -> None:
+    df = fruits_cars
+    out = df.select([pl.all().prefix("reverse_")])
+    assert out.columns == ["reverse_A", "reverse_fruits", "reverse_B", "reverse_cars"]

py-polars/tests/test_interop.py

@@ -111,12 +111,20 @@ def test_from_arrow() -> None:
     df = pl.from_arrow(data)
     assert df.shape == (3, 2)
 
+    # if not a PyArrow type, raise a ValueError
+    with pytest.raises(ValueError):
+        _ = pl.from_arrow([1, 2])  # type: ignore
+
 
 def test_from_pandas_dataframe() -> None:
     pd_df = pd.DataFrame([[1, 2, 3], [4, 5, 6]], columns=["a", "b", "c"])
     df = pl.from_pandas(pd_df)
     assert df.shape == (2, 3)
 
+    # if not a Pandas dataframe, raise a ValueError
+    with pytest.raises(ValueError):
+        _ = pl.from_pandas([1, 2])  # type: ignore
+
 
 def test_from_pandas_series() -> None:
     pd_series = pd.Series([1, 2, 3], name="pd")