Implicity convert series to DataFrame before doing the concatenation (pandas-dev#56257)

Author: LAPTOP-8CGF3UCA\Alain Khalil

pandas/core/reshape/concat.py

@@ -413,6 +413,10 @@ def __init__(
         copy: bool = True,
         sort: bool = False,
     ) -> None:
+        for i in range(len(objs)):
+            if isinstance(objs[i], ABCSeries):
+                objs[i] = objs[i].to_frame()
+        
         if isinstance(objs, (ABCSeries, ABCDataFrame, str)):
             raise TypeError(
                 "first argument must be an iterable of pandas "

pandas/tests/reshape/concat/test_concat.py

@@ -883,3 +883,10 @@ def test_concat_none_with_timezone_timestamp():
         result = concat([df1, df2], ignore_index=True)
     expected = DataFrame({"A": [None, pd.Timestamp("1990-12-20 00:00:00+00:00")]})
     tm.assert_frame_equal(result, expected)
+
+def test_concat_dataframe_and_series():
+    df1 = DataFrame({'A': [1, 2], 'B': [3, 4]})
+    s1 = Series([1, 2], name='A')
+    result = pd.concat([df1, s1])
+    expected_result = pd.concat([df1, s1.to_frame()])
+    assert result.equals(expected_result)