Inferred dtype at the end of df.explode()

Author: Santhosh18

pandas/core/frame.py

@@ -7007,6 +7007,7 @@ def explode(self, column: Union[str, Tuple]) -> "DataFrame":
         result = df.drop([column], axis=1).join(result)
         result.index = self.index.take(result.index)
         result = result.reindex(columns=self.columns, copy=False)
+        result = result.infer_objects()
 
         return result
 

pandas/tests/series/methods/test_explode.py

@@ -7,7 +7,7 @@
 
 def test_basic():
     s = pd.Series([[0, 1, 2], np.nan, [], (3, 4)], index=list("abcd"), name="foo")
-    result = s.explode()
+    result = s. explode()
     expected = pd.Series(
         [0, 1, 2, np.nan, np.nan, 3, 4], index=list("aaabcdd"), dtype=object, name="foo"
     )
@@ -118,3 +118,11 @@ def test_duplicate_index():
     result = s.explode()
     expected = pd.Series([1, 2, 3, 4], index=[0, 0, 0, 0], dtype=object)
     tm.assert_series_equal(result, expected)
+
+
+def test_inferred_dtype():
+    s = pd.Series([1,None,3])
+    df = pd.DataFrame({'A':[s,s,s,s], "B":1})
+    result = df.explode("A").dtypes.values
+    expected = np.array([np.dtype('float64'), np.dtype('int64')])
+    tm.assert_numpy_array_equal(result, expected)