BUG: Fix issue with old-style usage in convert_objects

pandas/core/generic.py

@@ -3,6 +3,7 @@
 import operator
 import weakref
 import gc
+
 import numpy as np
 import pandas.lib as lib
 
@@ -27,6 +28,7 @@
 from pandas.util.decorators import Appender, Substitution, deprecate_kwarg
 from pandas.core import config
 
+
 # goal is to be able to define the docs close to function, while still being
 # able to share
 _shared_docs = dict()
@@ -2473,6 +2475,26 @@ def convert_objects(self, datetime=False, numeric=False,
         -------
         converted : same as input object
         """
+
+        # Deprecation code to handle usage change
+        issue_warning = False
+        if datetime == 'coerce':
+            datetime = coerce = True
+            numeric = timedelta = False
+            issue_warning = True
+        elif numeric == 'coerce':
+            numeric = coerce = True
+            datetime = timedelta = False
+            issue_warning = True
+        elif timedelta == 'coerce':
+            timedelta = coerce = True
+            datetime = numeric = False
+            issue_warning = True
+        if issue_warning:
+            warnings.warn("The use of 'coerce' as an input is deprecated. "
+                          "Instead set coerce=True.",
+                          FutureWarning)
+
         return self._constructor(
             self._data.convert(datetime=datetime,
                                numeric=numeric,

pandas/tests/test_series.py

@@ -6209,6 +6209,34 @@ def test_convert_objects(self):
             result = s.convert_objects(datetime=True, coerce=True)
             assert_series_equal(result, expected)
 
+    # GH 10601
+    # Remove test after deprecation to convert_objects is final
+    def test_convert_objects_old_style_deprecation(self):
+        s = Series(['foo', 'bar', 1, 1.0], dtype='O')
+        with warnings.catch_warnings(record=True) as w:
+            warnings.simplefilter('always', FutureWarning)
+            new_style = s.convert_objects(datetime=True, coerce=True)
+            old_style = s.convert_objects(convert_dates='coerce')
+            self.assertEqual(len(w), 2)
+        assert_series_equal(new_style, old_style)
+
+        with warnings.catch_warnings(record=True) as w:
+            warnings.simplefilter('always', FutureWarning)
+            new_style = s.convert_objects(numeric=True, coerce=True)
+            old_style = s.convert_objects(convert_numeric='coerce')
+            self.assertEqual(len(w), 2)
+        assert_series_equal(new_style, old_style)
+
+        dt = datetime(2001, 1, 1, 0, 0)
+        td = dt - datetime(2000, 1, 1, 0, 0)
+        s = Series(['a', '3.1415', dt, td])
+        with warnings.catch_warnings(record=True) as w:
+            warnings.simplefilter('always', FutureWarning)
+            new_style = s.convert_objects(timedelta=True, coerce=True)
+            old_style = s.convert_objects(convert_timedeltas='coerce')
+            self.assertEqual(len(w), 2)
+        assert_series_equal(new_style, old_style)
+
     def test_convert_objects_no_arg_warning(self):
         s = Series(['1.0','2'])
         with warnings.catch_warnings(record=True) as w: