fix : remove memo usage

Author: vignesh14052002

pandas/_libs/parsers.pyx

@@ -2122,7 +2122,6 @@ def sanitize_objects(ndarray[object] values, set na_values) -> int:
         Py_ssize_t i, n
         object val, onan
         Py_ssize_t na_count = 0
-        dict memo = {}
 
     n = len(values)
     onan = np.nan
@@ -2132,9 +2131,5 @@ def sanitize_objects(ndarray[object] values, set na_values) -> int:
         if val in na_values:
             values[i] = onan
             na_count += 1
-        elif val in memo:
-            values[i] = memo[val]
-        else:
-            memo[val] = val
 
     return na_count

pandas/tests/io/parser/common/test_common_basic.py

@@ -28,6 +28,7 @@
     compat,
 )
 import pandas._testing as tm
+from pandas._libs import parsers as libparsers
 
 pytestmark = pytest.mark.filterwarnings(
     "ignore:Passing a BlockManager to DataFrame:DeprecationWarning"
@@ -830,3 +831,12 @@ def test_read_seek(all_parsers):
             actual = parser.read_csv(file)
         expected = parser.read_csv(StringIO(content))
     tm.assert_frame_equal(actual, expected)
+
+def test_dtype_conversion_in_sanitization():
+    # GH60088
+    values = np.array([1,True],dtype=object)
+    expected = np.array([1,True],dtype=object)
+    libparsers.sanitize_objects(values,na_values=set())
+    for v,e in zip(values,expected):
+        assert v==e
+        assert type(v)==type(e)