from empty pandas table (#2518)

* from empty pandas table
pola-rs · Feb 2, 2022 · 7933b2e · 7933b2e
1 parent 78b991b
commit 7933b2e
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Showing 4 changed files with 18 additions and 2 deletions.
diff --git a/py-polars/Cargo.lock b/py-polars/Cargo.lock
diff --git a/py-polars/Cargo.toml b/py-polars/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name = "py-polars"
-version = "0.12.19"
+version = "0.12.20"
 authors = ["ritchie46 <ritchie46@gmail.com>"]
 documentation = "https://pola-rs.github.io/polars/py-polars/html/reference/index.html"
 edition = "2021"

diff --git a/py-polars/polars/internals/frame.py b/py-polars/polars/internals/frame.py
@@ -356,6 +356,9 @@ def _from_pandas(
         -------
         DataFrame
         """
+        if data.shape[0] == 0:
+            return DataFrame([pli.Series(name, data[name]) for name in data.columns])
+
         return cls._from_pydf(
             pandas_to_pydf(
                 data, columns=columns, rechunk=rechunk, nan_to_none=nan_to_none

diff --git a/py-polars/tests/test_interop.py b/py-polars/tests/test_interop.py
@@ -179,3 +179,16 @@ def test_numpy_to_lit() -> None:
     assert out == [1, 2, 3]
     out = pl.select(pl.lit(np.float32(0))).to_series().to_list()
     assert out == [0.0]
+
+
+def test_from_empty_pandas() -> None:
+    pandas_df = pd.DataFrame(
+        {
+            "A": [],
+            "fruits": [],
+        }
+    )
+
+    polars_df = pl.from_pandas(pandas_df)
+    assert polars_df.columns == ["A", "fruits"]
+    assert polars_df.dtypes == [pl.Float64, pl.Float64]