[SPARK-35599][PYTHON] Adjust check_exact parameter for older pd.testing

### What changes were proposed in this pull request?

Adjust the `check_exact` parameter for non-numeric columns to ensure pandas-on-Spark tests passed with all pandas versions.

### Why are the changes needed?

`pd.testing` utils are utilized in pandas-on-Spark tests.
Due to pandas-dev/pandas#35446, `check_exact=True` for non-numeric columns doesn't work for older pd.testing utils, e.g. `assert_series_equal`.  We wanted to adjust that to ensure pandas-on-Spark tests pass for all pandas versions.

### Does this PR introduce _any_ user-facing change?

No.

### How was this patch tested?

Existing unit tests.

Closes #32772 from xinrong-databricks/test_util.

Authored-by: Xinrong Meng <[email protected]>
Signed-off-by: Hyukjin Kwon <[email protected]>

Author: xinrong-meng

python/pyspark/testing/pandasutils.py

@@ -25,6 +25,7 @@
 
 import pandas as pd
 from pandas.api.types import is_list_like
+from pandas.core.dtypes.common import is_numeric_dtype
 from pandas.testing import assert_frame_equal, assert_index_equal, assert_series_equal
 
 from pyspark import pandas as ps
@@ -81,6 +82,12 @@ def assertPandasEqual(self, left, right, check_exact=True):
                 else:
                     kwargs = dict()
 
+                if LooseVersion(pd.__version__) < LooseVersion("1.1.1"):
+                    # Due to https://github.com/pandas-dev/pandas/issues/35446
+                    check_exact = check_exact \
+                        and all([is_numeric_dtype(dtype) for dtype in left.dtypes]) \
+                        and all([is_numeric_dtype(dtype) for dtype in right.dtypes])
+
                 assert_frame_equal(
                     left,
                     right,
@@ -102,7 +109,11 @@ def assertPandasEqual(self, left, right, check_exact=True):
                     kwargs = dict(check_freq=False)
                 else:
                     kwargs = dict()
-
+                if LooseVersion(pd.__version__) < LooseVersion("1.1.1"):
+                    # Due to https://github.com/pandas-dev/pandas/issues/35446
+                    check_exact = check_exact \
+                        and is_numeric_dtype(left.dtype) \
+                        and is_numeric_dtype(right.dtype)
                 assert_series_equal(
                     left,
                     right,
@@ -119,6 +130,11 @@ def assertPandasEqual(self, left, right, check_exact=True):
                 raise AssertionError(msg) from e
         elif isinstance(left, pd.Index) and isinstance(right, pd.Index):
             try:
+                if LooseVersion(pd.__version__) < LooseVersion("1.1.1"):
+                    # Due to https://github.com/pandas-dev/pandas/issues/35446
+                    check_exact = check_exact \
+                        and is_numeric_dtype(left.dtype) \
+                        and is_numeric_dtype(right.dtype)
                 assert_index_equal(left, right, check_exact=check_exact)
             except AssertionError as e:
                 msg = (