FIX-#5325: fix read_csv_glob with non-empty parse_dates dict

modin/core/io/text/csv_glob_dispatcher.py

@@ -151,10 +151,10 @@ def _read(cls, filepath_or_buffer, **kwargs):
                 if len(index_col) == 1:
                     index_col = index_col[0]
                 kwargs["index_col"] = index_col
-        empty_pd_df = pandas.read_csv(
-            filepath_or_buffer, **dict(kwargs, nrows=0, skipfooter=0)
+        pd_df_metadata = pandas.read_csv(
+            filepath_or_buffer, **dict(kwargs, nrows=1, skipfooter=0)
         )
-        column_names = empty_pd_df.columns
+        column_names = pd_df_metadata.columns
         skipfooter = kwargs.get("skipfooter", None)
         skiprows = kwargs.pop("skiprows", None)
         usecols_md = cls._validate_usecols_arg(usecols)
@@ -214,7 +214,9 @@ def _read(cls, filepath_or_buffer, **kwargs):
             if kwargs.get("encoding", None) is not None:
                 partition_kwargs["skiprows"] = 1
             # Launch tasks to read partitions
-            column_widths, num_splits = cls._define_metadata(empty_pd_df, column_names)
+            column_widths, num_splits = cls._define_metadata(
+                pd_df_metadata, column_names
+            )
 
             args = {
                 "num_splits": num_splits,
@@ -251,7 +253,7 @@ def _read(cls, filepath_or_buffer, **kwargs):
             index_objs = cls.materialize(index_ids)
             row_lengths = [len(o) for o in index_objs]
             new_index = index_objs[0].append(index_objs[1:])
-            new_index.name = empty_pd_df.index.name
+            new_index.name = pd_df_metadata.index.name
 
         # Compute dtypes by getting collecting and combining all of the partitions. The
         # reported dtypes from differing rows can be different based on the inference in
@@ -260,35 +262,6 @@ def _read(cls, filepath_or_buffer, **kwargs):
         dtypes = cls.get_dtypes(dtypes_ids) if len(dtypes_ids) > 0 else None
 
         partition_ids = cls.build_partition(partition_ids, row_lengths, column_widths)
-        # If parse_dates is present, the column names that we have might not be
-        # the same length as the returned column names. If we do need to modify
-        # the column names, we remove the old names from the column names and
-        # insert the new one at the front of the Index.
-        if parse_dates is not None:
-            # We have to recompute the column widths if `parse_dates` is set because
-            # we are not guaranteed to have the correct information regarding how many
-            # columns are on each partition.
-            column_widths = None
-            if isinstance(parse_dates, list):
-                for date in parse_dates:
-                    # Lists within the parse_dates list are sequences of
-                    # CSV columns that are parsed together as a single date
-                    # column. They can be a list of either string column names
-                    # or integer column indices. e.g. if parse_dates is
-                    # [[1, 2]] and columns at indices 1 and 2 are "b" and "c",
-                    # the output dataframe has the single date column "b_c". If
-                    # parse_dates is [["a", 1]] and the column at index 1 is
-                    # named "b", the output dataframe has the single date
-                    # column "a_b".
-                    if isinstance(date, list):
-                        for i, part in enumerate(date):
-                            if isinstance(part, int):
-                                date[i] = column_names[part]
-                        new_col_name = "_".join(date)
-                        column_names = column_names.drop(date).insert(0, new_col_name)
-            elif isinstance(parse_dates, dict):
-                for new_col_name, group in parse_dates.items():
-                    column_names = column_names.drop(group).insert(0, new_col_name)
         # Set the index for the dtypes to the column names
         if isinstance(dtypes, pandas.Series):
             dtypes.index = column_names

modin/experimental/pandas/test/test_io_exp.py

@@ -148,8 +148,6 @@ def test_read_csv_glob_4373(self):
         [pytest.param(value, id=id) for id, value in parse_dates_values_by_id.items()],
     )
     def test_read_single_csv_with_parse_dates(self, parse_dates):
-        if isinstance(parse_dates, dict):
-            pytest.xfail("raises KeyError when dict is not empty. See GH#5325")
         try:
             pandas_df = pandas.read_csv(time_parsing_csv_path, parse_dates=parse_dates)
         except Exception as pandas_exception: