BUG: pd.array failing to raise with DataFrame (#51167)

Author: jbrockmendel

doc/source/whatsnew/v2.0.0.rst

@@ -1334,6 +1334,7 @@ Metadata
 Other
 ^^^^^
 - Bug in :meth:`Series.searchsorted` inconsistent behavior when accepting :class:`DataFrame` as parameter ``value`` (:issue:`49620`)
+- Bug in :func:`array` failing to raise on :class:`DataFrame` inputs (:issue:`51167`)
 -
 
 .. ***DO NOT USE THIS SECTION***

pandas/core/construction.py

@@ -52,6 +52,7 @@
 )
 from pandas.core.dtypes.dtypes import PandasDtype
 from pandas.core.dtypes.generic import (
+    ABCDataFrame,
     ABCExtensionArray,
     ABCIndex,
     ABCPandasArray,
@@ -308,6 +309,8 @@ def array(
     if lib.is_scalar(data):
         msg = f"Cannot pass scalar '{data}' to 'pandas.array'."
         raise ValueError(msg)
+    elif isinstance(data, ABCDataFrame):
+        raise TypeError("Cannot pass DataFrame to 'pandas.array'")
 
     if dtype is None and isinstance(data, (ABCSeries, ABCIndex, ExtensionArray)):
         # Note: we exclude np.ndarray here, will do type inference on it

pandas/tests/arrays/test_array.py

@@ -343,6 +343,14 @@ def test_scalar_raises():
         pd.array(1)
 
 
+def test_dataframe_raises():
+    # GH#51167 don't accidentally cast to StringArray by doing inference on columns
+    df = pd.DataFrame([[1, 2], [3, 4]], columns=["A", "B"])
+    msg = "Cannot pass DataFrame to 'pandas.array'"
+    with pytest.raises(TypeError, match=msg):
+        pd.array(df)
+
+
 def test_bounds_check():
     # GH21796
     with pytest.raises(