[DLMED] fix CI tests

Signed-off-by: Nic Ma <nma@nvidia.com>

Author: Nic-Ma

monai/data/utils.py

@@ -38,13 +38,8 @@
 )
 from monai.utils.enums import Method
 
-if TYPE_CHECKING:
-    import pandas as pd
-    from pandas import DataFrame
-else:
-    pd, _ = optional_import("pandas")
-    DataFrame, _ = optional_import("pandas", name="DataFrame")
-
+pd, _ = optional_import("pandas")
+DataFrame, _ = optional_import("pandas", name="DataFrame")
 nib, _ = optional_import("nibabel")
 
 
@@ -996,7 +991,7 @@ def sorted_dict(item, key=None, reverse=False):
 
 
 def convert_tables_to_dicts(
-    dfs: Union[Sequence[DataFrame], DataFrame],
+    dfs,
     row_indices: Optional[Sequence[Union[int, str]]] = None,
     col_names: Optional[Sequence[str]] = None,
     col_groups: Optional[Dict[str, Sequence[str]]] = None,
@@ -1020,6 +1015,7 @@ def convert_tables_to_dicts(
         kwargs: additional arguments for `pandas.merge()` API to join tables.
 
     """
+    dfs: Union[Sequence[DataFrame], DataFrame]
     df = reduce(lambda l, r: pd.merge(l, r, **kwargs), ensure_tuple(dfs))
     # parse row indices
     rows: List[Union[int, str]] = []

tests/test_csv_iterable_dataset.py

@@ -11,6 +11,7 @@
 
 import os
 import tempfile
+import sys
 import unittest
 
 import numpy as np
@@ -160,7 +161,9 @@ def prepare_csv_file(data, filepath):
 
             # test multiple processes loading
             dataset = CSVIterableDataset(filepath1, transform=ToNumpyd(keys="label"))
-            dataloader = DataLoader(dataset=dataset, num_workers=2, batch_size=2)
+            # num workers = 0 for mac
+            num_workers = 0 if sys.platform == "darwin" else 2
+            dataloader = DataLoader(dataset=dataset, num_workers=num_workers, batch_size=2)
             for item in dataloader:
                 # test the last item which only has 1 data
                 if len(item) == 1: