gfyoung review

Clean error message, check for error in tests, fix typo in whatsnew.

Author: jschendel

doc/source/whatsnew/v0.21.0.txt

@@ -358,7 +358,7 @@ Previously, :func:`to_datetime` did not localize datetime ``Series`` data when `
 
 Additionally, DataFrames with datetime columns that were parsed by :func:`read_sql_table` and :func:`read_sql_query` will also be localized to UTC only if the original SQL columns were timezone aware datetime columns.
 
-.. _whatsnew_0200.api.consistency_of_range_functions:
+.. _whatsnew_0210.api.consistency_of_range_functions:
 
 Consistency of Range Functions
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -386,11 +386,11 @@ New Behavior:
 
   In [2]: pd.interval_range(start=0, end=4, periods=6)
   ---------------------------------------------------------------------------
-  ValueError: Must specify exactly two of start, end, or periods
+  ValueError: Of the three parameters, start, end, and periods, exactly two must be specified
 
   In [3]: pd.period_range(start='2017Q1', end='2017Q4', periods=6, freq='Q')  
   ---------------------------------------------------------------------------
-  ValueError: Must specify exactly two of start, end, or periods
+  ValueError: Of the three parameters, start, end, and periods, exactly two must be specified
 
 Additionally, the endpoint parameter ``end`` was not included in the intervals produced by ``interval_range``.  However, all other range functions include ``end`` in their output.  To promote consistency among the range functions, ``interval_range`` will now include ``end`` as the right endpoint of the final interval, except if ``freq`` is specified in a way which skips ``end``.
 

pandas/core/indexes/datetimes.py

@@ -412,8 +412,8 @@ def __new__(cls, data=None,
     def _generate(cls, start, end, periods, name, offset,
                   tz=None, normalize=False, ambiguous='raise', closed=None):
         if com._count_not_none(start, end, periods) != 2:
-            msg = 'Must specify exactly two of start, end, or periods'
-            raise ValueError(msg)
+            raise ValueError('Of the three parameters, start, end, and '
+                             'periods, exactly two must be specified')
 
         _normalized = True
 
@@ -2031,7 +2031,8 @@ def date_range(start=None, end=None, periods=None, freq='D', tz=None,
 
     Notes
     -----
-    Exactly two of start, end, or periods must be specified
+    Of the three parameters, ``start``, ``end``, and ``periods``, exactly two
+    must be specified.
 
     To learn more about the frequency strings, please see `this link
     <http://pandas.pydata.org/pandas-docs/stable/timeseries.html#offset-aliases>`__.
@@ -2074,7 +2075,8 @@ def bdate_range(start=None, end=None, periods=None, freq='B', tz=None,
 
     Notes
     -----
-    Exactly two of start, end, or periods must be specified
+    Of the three parameters, ``start``, ``end``, and ``periods``, exactly two
+    must be specified.
 
     To learn more about the frequency strings, please see `this link
     <http://pandas.pydata.org/pandas-docs/stable/timeseries.html#offset-aliases>`__.
@@ -2128,7 +2130,8 @@ def cdate_range(start=None, end=None, periods=None, freq='C', tz=None,
 
     Notes
     -----
-    Exactly two of start, end, or periods must be specified
+    Of the three parameters, ``start``, ``end``, and ``periods``, exactly two
+    must be specified.
 
     To learn more about the frequency strings, please see `this link
     <http://pandas.pydata.org/pandas-docs/stable/timeseries.html#offset-aliases>`__.

pandas/core/indexes/interval.py

@@ -1048,14 +1048,16 @@ def interval_range(start=None, end=None, freq=None, periods=None,
 
     Notes
     -----
-    Exactly two of start, end, or periods must be specified
+    Of the three parameters, ``start``, ``end``, and ``periods``, exactly two
+    must be specified.
 
     Returns
     -------
     rng : IntervalIndex
     """
     if com._count_not_none(start, end, periods) != 2:
-        raise ValueError('Must specify exactly two of start, end, or periods')
+        raise ValueError('Of the three parameters, start, end, and periods, '
+                         'exactly two must be specified')
 
     if freq is None:
         freq = 1

pandas/core/indexes/period.py

@@ -1052,7 +1052,8 @@ def tz_localize(self, tz, infer_dst=False):
 
 def _get_ordinal_range(start, end, periods, freq, mult=1):
     if com._count_not_none(start, end, periods) != 2:
-        raise ValueError('Must specify exactly two of start, end, or periods')
+        raise ValueError('Of the three parameters, start, end, and periods, '
+                         'exactly two must be specified')
 
     if freq is not None:
         _, mult = _gfc(freq)
@@ -1173,7 +1174,8 @@ def period_range(start=None, end=None, periods=None, freq='D', name=None):
 
     Notes
     -----
-    Exactly two of start, end, or periods must be specified
+    Of the three parameters, ``start``, ``end``, and ``periods``, exactly two
+    must be specified.
 
     To learn more about the frequency strings, please see `this link
     <http://pandas.pydata.org/pandas-docs/stable/timeseries.html#offset-aliases>`__.
@@ -1182,5 +1184,9 @@ def period_range(start=None, end=None, periods=None, freq='D', name=None):
     -------
     prng : PeriodIndex
     """
+    if com._count_not_none(start, end, periods) != 2:
+        raise ValueError('Of the three parameters, start, end, and periods, '
+                         'exactly two must be specified')
+
     return PeriodIndex(start=start, end=end, periods=periods,
                        freq=freq, name=name)

pandas/core/indexes/timedeltas.py

@@ -234,8 +234,8 @@ def __new__(cls, data=None, unit=None,
     @classmethod
     def _generate(cls, start, end, periods, name, offset, closed=None):
         if com._count_not_none(start, end, periods) != 2:
-            msg = 'Must specify exactly two of start, end, or periods'
-            raise ValueError(msg)
+            raise ValueError('Of the three parameters, start, end, and '
+                             'periods, exactly two must be specified')
 
         if start is not None:
             start = Timedelta(start)
@@ -986,7 +986,8 @@ def timedelta_range(start=None, end=None, periods=None, freq='D',
 
     Notes
     -----
-    Exactly two of start, end, or periods must be specified.
+    Of the three parameters, ``start``, ``end``, and ``periods``, exactly two
+    must be specified.
 
     To learn more about the frequency strings, please see `this link
     <http://pandas.pydata.org/pandas-docs/stable/timeseries.html#offset-aliases>`__.

pandas/tests/indexes/datetimes/test_date_range.py

@@ -107,7 +107,9 @@ def test_date_range_ambiguous_arguments(self):
         start = datetime(2011, 1, 1, 5, 3, 40)
         end = datetime(2011, 1, 1, 8, 9, 40)
 
-        with pytest.raises(ValueError):
+        msg = ('Of the three parameters, start, end, and periods, '
+               'exactly two must be specified')
+        with tm.assert_raises_regex(ValueError, msg):
             date_range(start, end, periods=10, freq='s')
 
     def test_date_range_businesshour(self):
@@ -146,25 +148,28 @@ def test_date_range_businesshour(self):
 
     def test_range_misspecified(self):
         # GH #1095
-        with pytest.raises(ValueError):
+        msg = ('Of the three parameters, start, end, and periods, '
+               'exactly two must be specified')
+
+        with tm.assert_raises_regex(ValueError, msg):
             date_range(start='1/1/2000')
 
-        with pytest.raises(ValueError):
+        with tm.assert_raises_regex(ValueError, msg):
             date_range(end='1/1/2000')
 
-        with pytest.raises(ValueError):
+        with tm.assert_raises_regex(ValueError, msg):
             date_range(periods=10)
 
-        with pytest.raises(ValueError):
+        with tm.assert_raises_regex(ValueError, msg):
             date_range(start='1/1/2000', freq='H')
 
-        with pytest.raises(ValueError):
+        with tm.assert_raises_regex(ValueError, msg):
             date_range(end='1/1/2000', freq='H')
 
-        with pytest.raises(ValueError):
+        with tm.assert_raises_regex(ValueError, msg):
             date_range(periods=10, freq='H')
 
-        with pytest.raises(ValueError):
+        with tm.assert_raises_regex(ValueError, msg):
             date_range()
 
     def test_compat_replace(self):

pandas/tests/indexes/period/test_construction.py

@@ -440,7 +440,8 @@ def test_constructor_error(self):
         with tm.assert_raises_regex(ValueError, msg):
             PeriodIndex(start=start, end=end_intv)
 
-        msg = 'Must specify exactly two of start, end, or periods'
+        msg = ('Of the three parameters, start, end, and periods, '
+               'exactly two must be specified')
         with tm.assert_raises_regex(ValueError, msg):
             PeriodIndex(start=start)
 

pandas/tests/indexes/period/test_period_range.py

@@ -35,18 +35,20 @@ def test_construction(self, freq):
 
     def test_errors(self):
         # not enough params
-        with pytest.raises(ValueError):
+        msg = ('Of the three parameters, start, end, and periods, '
+               'exactly two must be specified')
+        with tm.assert_raises_regex(ValueError, msg):
             period_range(start='2017Q1')
 
-        with pytest.raises(ValueError):
+        with tm.assert_raises_regex(ValueError, msg):
             period_range(end='2017Q1')
 
-        with pytest.raises(ValueError):
+        with tm.assert_raises_regex(ValueError, msg):
             period_range(periods=5)
 
-        with pytest.raises(ValueError):
+        with tm.assert_raises_regex(ValueError, msg):
             period_range()
 
         # too many params
-        with pytest.raises(ValueError):
+        with tm.assert_raises_regex(ValueError, msg):
             period_range(start='2017Q1', end='2018Q1', periods=8, freq='Q')

pandas/tests/indexes/test_interval.py

@@ -759,27 +759,31 @@ def test_construction(self, closed):
 
     def test_errors(self):
         # not enough params
-        with pytest.raises(ValueError):
+        msg = ('Of the three parameters, start, end, and periods, '
+               'exactly two must be specified')
+
+        with tm.assert_raises_regex(ValueError, msg):
             interval_range(start=0)
 
-        with pytest.raises(ValueError):
+        with tm.assert_raises_regex(ValueError, msg):
             interval_range(end=5)
 
-        with pytest.raises(ValueError):
+        with tm.assert_raises_regex(ValueError, msg):
             interval_range(periods=2)
 
-        with pytest.raises(ValueError):
+        with tm.assert_raises_regex(ValueError, msg):
             interval_range()
 
         # too many params
-        with pytest.raises(ValueError):
+        with tm.assert_raises_regex(ValueError, msg):
             interval_range(start=0, end=5, periods=6)
 
         # mixed units
-        with pytest.raises(ValueError):
+        msg = 'start, end, freq need to be the same type'
+        with tm.assert_raises_regex(ValueError, msg):
             interval_range(start=0, end=Timestamp('20130101'), freq=2)
 
-        with pytest.raises(ValueError):
+        with tm.assert_raises_regex(ValueError, msg):
             interval_range(start=0, end=10, freq=Timedelta('1day'))
 
 

pandas/tests/indexes/timedeltas/test_timedelta_range.py

@@ -1,5 +1,4 @@
 import numpy as np
-import pytest
 import pandas as pd
 import pandas.util.testing as tm
 from pandas.tseries.offsets import Day, Second
@@ -52,18 +51,20 @@ def test_timedelta_range(self):
 
     def test_errors(self):
         # not enough params
-        with pytest.raises(ValueError):
+        msg = ('Of the three parameters, start, end, and periods, '
+               'exactly two must be specified')
+        with tm.assert_raises_regex(ValueError, msg):
             timedelta_range(start='0 days')
 
-        with pytest.raises(ValueError):
+        with tm.assert_raises_regex(ValueError, msg):
             timedelta_range(end='5 days')
 
-        with pytest.raises(ValueError):
+        with tm.assert_raises_regex(ValueError, msg):
             timedelta_range(periods=2)
 
-        with pytest.raises(ValueError):
+        with tm.assert_raises_regex(ValueError, msg):
             timedelta_range()
 
         # too many params
-        with pytest.raises(ValueError):
+        with tm.assert_raises_regex(ValueError, msg):
             timedelta_range(start='0 days', end='5 days', periods=10)