code: def test_fwf_regression():
      # see gh-3594
      #
      # Turns out "T060" is parsable as a datetime slice!
      tz_list = [1, 10, 20, 30, 60, 80, 100]
      widths = [16] + [8] * len(tz_list)
      names = ["SST"] + [f"T{z:03d}" for z in tz_list[1:]]
  
      data = """  2009164202000   9.5403  9.4105  8.6571  7.8372  6.0612  5.8843  5.5192
  2009164203000   9.5435  9.2010  8.6167  7.8176  6.0804  5.8728  5.4869
  2009164204000   9.5873  9.1326  8.4694  7.5889  6.0422  5.8526  5.4657
  2009164205000   9.5810  9.0896  8.4009  7.4652  6.0322  5.8189  5.4379
  2009164210000   9.6034  9.0897  8.3822  7.4905  6.0908  5.7904  5.4039
  """
  
      with tm.assert_produces_warning(
          FutureWarning, match="use 'date_format' instead"
      ):
          result = read_fwf(
              StringIO(data),
              index_col=0,
              header=None,
              names=names,
              widths=widths,
              parse_dates=True,
              date_parser=lambda s: datetime.strptime(s, "%Y%j%H%M%S"),
          )
      expected = DataFrame(
          [
              [9.5403, 9.4105, 8.6571, 7.8372, 6.0612, 5.8843, 5.5192],
              [9.5435, 9.2010, 8.6167, 7.8176, 6.0804, 5.8728, 5.4869],
              [9.5873, 9.1326, 8.4694, 7.5889, 6.0422, 5.8526, 5.4657],
              [9.5810, 9.0896, 8.4009, 7.4652, 6.0322, 5.8189, 5.4379],
              [9.6034, 9.0897, 8.3822, 7.4905, 6.0908, 5.7904, 5.4039],
          ],
          index=DatetimeIndex(
              [
                  "2009-06-13 20:20:00",
                  "2009-06-13 20:30:00",
                  "2009-06-13 20:40:00",
                  "2009-06-13 20:50:00",
                  "2009-06-13 21:00:00",
              ]
          ),
          columns=[
              "SST",
              "T010",
              "T020",
              "T030",
              "T060",
              "T080",
              "T100",
          ],
      )
      tm.assert_frame_equal(result, expected)
      result = read_fwf(
          StringIO(data),
          index_col=0,
          header=None,
          names=names,
          widths=widths,
          parse_dates=True,
          date_format="%Y%j%H%M%S",
      )
      tm.assert_frame_equal(result, expected)
  
imports: from datetime import datetime
  from io import BytesIO, StringIO
  from pathlib import Path
  import numpy
  import pytest
  from pandas.errors import EmptyDataError
  import pandas
  from pandas import DataFrame, DatetimeIndex
  import pandas._testing
  from pandas.core.arrays import ArrowStringArray, StringArray
  from pandas.io.common import urlopen
  from pandas.io.parsers import read_csv, read_fwf
label_desc: Use image node_id 13 for calling a global function with example usage: test_fwf_regression() without return types