DEPR: Deprecate parse_all_fields in pandas.io.date_converters and upd…

…ate tests
pandas-dev · jreback · Sep 12, 2020 · Aug 15, 2020 · Aug 15, 2020 · Aug 15, 2020
commit eed8f16b54f873f84007104abd4c76f62d2416eb
diff --git a/pandas/io/date_converters.py b/pandas/io/date_converters.py
@@ -3,8 +3,6 @@
 
 import numpy as np
 
-from pandas._libs.tslibs import parsing
-
 from pandas import to_datetime
 
 
@@ -51,16 +49,43 @@ def parse_date_fields(year_col, month_col, day_col):
 
 
 def parse_all_fields(year_col, month_col, day_col, hour_col, minute_col, second_col):
-    year_col = _maybe_cast(year_col)
-    month_col = _maybe_cast(month_col)
-    day_col = _maybe_cast(day_col)
-    hour_col = _maybe_cast(hour_col)
-    minute_col = _maybe_cast(minute_col)
-    second_col = _maybe_cast(second_col)
-    return parsing.try_parse_datetime_components(
-        year_col, month_col, day_col, hour_col, minute_col, second_col
+    """Convert separate columns with years, months, days, hours, minutes and seconds
+     into a single datetime column
+
+    .. deprecated:: 1.1.0
+        Use pd.to_datetime({"year": year_col, "month": month_col, "day": day_col,
+        "hour": hour_col, "minute": minute_col, second": second_col}) instead to get
+        a Pandas Series.
+        Use ser = pd.to_datetime({"year": year_col, "month": month_col, "day": day_col,
+        "hour": hour_col, "minute": minute_col, second": second_col}) and
+        np.array([s.to_pydatetime() for s in ser]) instead to get a Numpy array.
+    """
+
+    warnings.warn(
+        """
+        Use pd.to_datetime({"year": year_col, "month": month_col, "day": day_col,
+        "hour": hour_col, "minute": minute_col, second": second_col}) instead to get a Pandas Series.
+        Use ser = pd.to_datetime({"year": year_col, "month": month_col, "day": day_col,
+        "hour": hour_col, "minute": minute_col, second": second_col}) and
+        np.array([s.to_pydatetime() for s in ser]) instead to get a Numpy array.
+""",  # noqa: E501
+        FutureWarning,
+        stacklevel=2,
     )
 
+    ser = to_datetime(
+        {
+            "year": year_col,
+            "month": month_col,
+            "day": day_col,
+            "hour": hour_col,
+            "minute": minute_col,
+            "second": second_col,
+        }
+    )
+
+    return np.array([s.to_pydatetime() for s in ser])
+
 
 def generic_parser(parse_func, *cols):
     N = _check_columns(cols)

diff --git a/pandas/tests/io/parser/test_parse_dates.py b/pandas/tests/io/parser/test_parse_dates.py
@@ -23,8 +23,6 @@
 import pandas._testing as tm
 from pandas.core.indexes.datetimes import date_range
 
-import pandas.io.date_converters as conv
-
 # constant
 _DEFAULT_DATETIME = datetime(1, 1, 1)
 
@@ -1290,6 +1288,7 @@ def test_parse_date_fields(all_parsers):
 
 
 def test_parse_date_all_fields(all_parsers):
+
     parser = all_parsers
     data = """\
 year,month,day,hour,minute,second,a,b
@@ -1299,7 +1298,7 @@ def test_parse_date_all_fields(all_parsers):
     result = parser.read_csv(
         StringIO(data),
         header=0,
-        date_parser=conv.parse_all_fields,
+        date_parser=lambda x: pd.to_datetime(x, format="%Y %m %d %H %M %S"),
         parse_dates={"ymdHMS": [0, 1, 2, 3, 4, 5]},
     )
     expected = DataFrame(
@@ -1322,7 +1321,8 @@ def test_datetime_fractional_seconds(all_parsers):
     result = parser.read_csv(
         StringIO(data),
         header=0,
-        date_parser=conv.parse_all_fields,
+        # date_parser=conv.parse_all_fields,
+        date_parser=lambda x: pd.to_datetime(x, format="%Y %m %d %H %M %S.%f"),
         parse_dates={"ymdHMS": [0, 1, 2, 3, 4, 5]},
     )
     expected = DataFrame(

diff --git a/pandas/tests/io/test_date_converters.py b/pandas/tests/io/test_date_converters.py
@@ -36,7 +36,8 @@ def test_parse_all_fields():
     days = np.array([3, 4])
     years = np.array([2007, 2008])
     months = np.array([1, 2])
-
-    result = conv.parse_all_fields(years, months, days, hours, minutes, seconds)
     expected = np.array([datetime(2007, 1, 3, 5, 7, 9), datetime(2008, 2, 4, 6, 8, 0)])
-    tm.assert_numpy_array_equal(result, expected)
+
+    with tm.assert_produces_warning(FutureWarning):
+        result = conv.parse_all_fields(years, months, days, hours, minutes, seconds)
+        tm.assert_numpy_array_equal(result, expected)