TST: allow assert_almost_equal to handle pandas instances

Closes #11584.    Because many existing tests expects
``assert_almost_equal`` to compare ``pandas`` instances, it looks
better to call appropriate test functions rather than raise.     I've
also fixed some failure cases caused by the change (comparing
``Series`` and ``list``, etc).

Author: sinhrks <[email protected]>

Closes #12247 from sinhrks/assert_almost and squashes the following commits:

dbf4cc6 [sinhrks] TST: allow assert_almost_equal to handle pandas instances

Author: sinhrks

Diff for: pandas/computation/tests/test_eval.py

@@ -1580,7 +1580,7 @@ def test_unary_functions(self):
             expr = "{0}(a)".format(fn)
             got = self.eval(expr)
             expect = getattr(np, fn)(a)
-            pd.util.testing.assert_almost_equal(got, expect)
+            tm.assert_series_equal(got, expect, check_names=False)
 
     def test_binary_functions(self):
         df = DataFrame({'a': np.random.randn(10),
@@ -1601,7 +1601,7 @@ def test_df_use_case(self):
                 parser=self.parser, inplace=True)
         got = df.e
         expect = np.arctan2(np.sin(df.a), df.b)
-        pd.util.testing.assert_almost_equal(got, expect)
+        tm.assert_series_equal(got, expect, check_names=False)
 
     def test_df_arithmetic_subexpression(self):
         df = DataFrame({'a': np.random.randn(10),
@@ -1611,7 +1611,7 @@ def test_df_arithmetic_subexpression(self):
                 parser=self.parser, inplace=True)
         got = df.e
         expect = np.sin(df.a + df.b)
-        pd.util.testing.assert_almost_equal(got, expect)
+        tm.assert_series_equal(got, expect, check_names=False)
 
     def check_result_type(self, dtype, expect_dtype):
         df = DataFrame({'a': np.random.randn(10).astype(dtype)})
@@ -1623,7 +1623,7 @@ def check_result_type(self, dtype, expect_dtype):
         expect = np.sin(df.a)
         self.assertEqual(expect.dtype, got.dtype)
         self.assertEqual(expect_dtype, got.dtype)
-        pd.util.testing.assert_almost_equal(got, expect)
+        tm.assert_series_equal(got, expect, check_names=False)
 
     def test_result_types(self):
         self.check_result_type(np.int32, np.float64)

Diff for: pandas/io/tests/test_cparser.py

@@ -130,8 +130,8 @@ def test_integer_thousands_alt(self):
                                 thousands='.', header=None)
         result = reader.read()
 
-        expected = [123456, 12500]
-        tm.assert_almost_equal(result[0], expected)
+        expected = DataFrame([123456, 12500])
+        tm.assert_frame_equal(result, expected)
 
     def test_skip_bad_lines(self):
         # too many lines, see #2430 for why

Diff for: pandas/sparse/tests/test_sparse.py

@@ -440,7 +440,8 @@ def _compare(idx):
 
         # Corner case
         sp = SparseSeries(np.ones(10) * nan)
-        assert_almost_equal(sp.take([0, 1, 2, 3, 4]), np.repeat(nan, 5))
+        exp = pd.Series(np.repeat(nan, 5))
+        tm.assert_series_equal(sp.take([0, 1, 2, 3, 4]), exp)
 
     def test_setitem(self):
         self.bseries[5] = 7.
@@ -1872,8 +1873,10 @@ def test_setitem(self):
 
         assert_sp_frame_equal(self.panel['ItemE'], self.panel['ItemC'])
         assert_sp_frame_equal(self.panel['ItemF'], self.panel['ItemC'])
-        assert_almost_equal(self.panel.items, ['ItemA', 'ItemB', 'ItemC',
-                                               'ItemD', 'ItemE', 'ItemF'])
+
+        expected = pd.Index(['ItemA', 'ItemB', 'ItemC',
+                             'ItemD', 'ItemE', 'ItemF'])
+        tm.assert_index_equal(self.panel.items, expected)
 
         self.assertRaises(Exception, self.panel.__setitem__, 'item6', 1)
 
@@ -1890,11 +1893,12 @@ def _check_loc(item, major, minor, val=1.5):
 
     def test_delitem_pop(self):
         del self.panel['ItemB']
-        assert_almost_equal(self.panel.items, ['ItemA', 'ItemC', 'ItemD'])
+        tm.assert_index_equal(self.panel.items,
+                              pd.Index(['ItemA', 'ItemC', 'ItemD']))
         crackle = self.panel['ItemC']
         pop = self.panel.pop('ItemC')
         self.assertIs(pop, crackle)
-        assert_almost_equal(self.panel.items, ['ItemA', 'ItemD'])
+        tm.assert_almost_equal(self.panel.items, pd.Index(['ItemA', 'ItemD']))
 
         self.assertRaises(KeyError, self.panel.__delitem__, 'ItemC')
 

Diff for: pandas/tests/frame/test_alter_axes.py

@@ -10,8 +10,7 @@
 from pandas import DataFrame, Series, Index, MultiIndex, RangeIndex
 import pandas as pd
 
-from pandas.util.testing import (assert_almost_equal,
-                                 assert_series_equal,
+from pandas.util.testing import (assert_series_equal,
                                  assert_frame_equal,
                                  assertRaisesRegexp)
 
@@ -447,7 +446,7 @@ def test_reset_index(self):
                                            stacked.index.labels)):
             values = lev.take(lab)
             name = names[i]
-            assert_almost_equal(values, deleveled[name])
+            tm.assert_index_equal(values, Index(deleveled[name]))
 
         stacked.index.names = [None, None]
         deleveled2 = stacked.reset_index()

Diff for: pandas/tests/frame/test_constructors.py

@@ -28,8 +28,7 @@
 
 from pandas.core.dtypes import DatetimeTZDtype
 
-from pandas.util.testing import (assert_almost_equal,
-                                 assert_numpy_array_equal,
+from pandas.util.testing import (assert_numpy_array_equal,
                                  assert_series_equal,
                                  assert_frame_equal,
                                  assertRaisesRegexp)
@@ -359,7 +358,7 @@ def test_constructor_dict_block(self):
         expected = [[4., 3., 2., 1.]]
         df = DataFrame({'d': [4.], 'c': [3.], 'b': [2.], 'a': [1.]},
                        columns=['d', 'c', 'b', 'a'])
-        assert_almost_equal(df.values, expected)
+        tm.assert_numpy_array_equal(df.values, expected)
 
     def test_constructor_dict_cast(self):
         # cast float tests

Diff for: pandas/tests/frame/test_indexing.py

@@ -1555,7 +1555,7 @@ def testit(df):
                         'mask_c': [False, True, False, True]})
         df['mask'] = df.lookup(df.index, 'mask_' + df['label'])
         exp_mask = alt(df, df.index, 'mask_' + df['label'])
-        assert_almost_equal(df['mask'], exp_mask)
+        tm.assert_series_equal(df['mask'], pd.Series(exp_mask, name='mask'))
         self.assertEqual(df['mask'].dtype, np.bool_)
 
         with tm.assertRaises(KeyError):
@@ -2070,7 +2070,9 @@ def test_xs_corner(self):
         df['E'] = 3.
 
         xs = df.xs(0)
-        assert_almost_equal(xs, [1., 'foo', 2., 'bar', 3.])
+        exp = pd.Series([1., 'foo', 2., 'bar', 3.],
+                        index=list('ABCDE'), name=0)
+        tm.assert_series_equal(xs, exp)
 
         # no columns but Index(dtype=object)
         df = DataFrame(index=['a', 'b', 'c'])

Diff for: pandas/tests/frame/test_mutate_columns.py

@@ -7,8 +7,7 @@
 
 from pandas import DataFrame, Series
 
-from pandas.util.testing import (assert_almost_equal,
-                                 assert_series_equal,
+from pandas.util.testing import (assert_series_equal,
                                  assert_frame_equal,
                                  assertRaisesRegexp)
 
@@ -125,12 +124,12 @@ def test_insert(self):
 
         df.insert(0, 'foo', df['a'])
         self.assert_numpy_array_equal(df.columns, ['foo', 'c', 'b', 'a'])
-        assert_almost_equal(df['a'], df['foo'])
+        tm.assert_series_equal(df['a'], df['foo'], check_names=False)
 
         df.insert(2, 'bar', df['c'])
         self.assert_numpy_array_equal(df.columns,
                                       ['foo', 'c', 'bar', 'b', 'a'])
-        assert_almost_equal(df['c'], df['bar'])
+        tm.assert_almost_equal(df['c'], df['bar'], check_names=False)
 
         # diff dtype
 

Diff for: pandas/tests/series/test_analytics.py

@@ -960,10 +960,10 @@ def test_rank(self):
         filled = self.ts.fillna(np.inf)
 
         # rankdata returns a ndarray
-        exp = Series(rankdata(filled), index=filled.index)
+        exp = Series(rankdata(filled), index=filled.index, name='ts')
         exp[mask] = np.nan
 
-        assert_almost_equal(ranks, exp)
+        tm.assert_series_equal(ranks, exp)
 
         iseries = Series(np.arange(5).repeat(2))
 

Diff for: pandas/tests/series/test_constructors.py

@@ -16,7 +16,7 @@
 
 from pandas.compat import lrange, range, zip, OrderedDict, long
 from pandas import compat
-from pandas.util.testing import assert_series_equal, assert_almost_equal
+from pandas.util.testing import assert_series_equal
 import pandas.util.testing as tm
 
 from .common import TestData
@@ -213,7 +213,7 @@ def test_constructor_maskedarray(self):
 
     def test_constructor_default_index(self):
         s = Series([0, 1, 2])
-        assert_almost_equal(s.index, np.arange(3))
+        tm.assert_index_equal(s.index, pd.Index(np.arange(3)))
 
     def test_constructor_corner(self):
         df = tm.makeTimeDataFrame()

Diff for: pandas/tests/series/test_operators.py

@@ -139,13 +139,15 @@ def test_div(self):
         assert_series_equal(result, expected)
 
     def test_operators(self):
-        def _check_op(series, other, op, pos_only=False):
+        def _check_op(series, other, op, pos_only=False,
+                      check_dtype=True):
             left = np.abs(series) if pos_only else series
             right = np.abs(other) if pos_only else other
 
             cython_or_numpy = op(left, right)
             python = left.combine(right, op)
-            tm.assert_almost_equal(cython_or_numpy, python)
+            tm.assert_series_equal(cython_or_numpy, python,
+                                   check_dtype=check_dtype)
 
         def check(series, other):
             simple_ops = ['add', 'sub', 'mul', 'truediv', 'floordiv', 'mod']
@@ -169,15 +171,15 @@ def check(series, other):
         check(self.ts, self.ts[::2])
         check(self.ts, 5)
 
-        def check_comparators(series, other):
-            _check_op(series, other, operator.gt)
-            _check_op(series, other, operator.ge)
-            _check_op(series, other, operator.eq)
-            _check_op(series, other, operator.lt)
-            _check_op(series, other, operator.le)
+        def check_comparators(series, other, check_dtype=True):
+            _check_op(series, other, operator.gt, check_dtype=check_dtype)
+            _check_op(series, other, operator.ge, check_dtype=check_dtype)
+            _check_op(series, other, operator.eq, check_dtype=check_dtype)
+            _check_op(series, other, operator.lt, check_dtype=check_dtype)
+            _check_op(series, other, operator.le, check_dtype=check_dtype)
 
         check_comparators(self.ts, 5)
-        check_comparators(self.ts, self.ts + 1)
+        check_comparators(self.ts, self.ts + 1, check_dtype=False)
 
     def test_operators_empty_int_corner(self):
         s1 = Series([], [], dtype=np.int32)
@@ -1256,10 +1258,14 @@ def test_operators_frame(self):
         # rpow does not work with DataFrame
         df = DataFrame({'A': self.ts})
 
-        tm.assert_almost_equal(self.ts + self.ts, self.ts + df['A'])
-        tm.assert_almost_equal(self.ts ** self.ts, self.ts ** df['A'])
-        tm.assert_almost_equal(self.ts < self.ts, self.ts < df['A'])
-        tm.assert_almost_equal(self.ts / self.ts, self.ts / df['A'])
+        tm.assert_series_equal(self.ts + self.ts, self.ts + df['A'],
+                               check_names=False)
+        tm.assert_series_equal(self.ts ** self.ts, self.ts ** df['A'],
+                               check_names=False)
+        tm.assert_series_equal(self.ts < self.ts, self.ts < df['A'],
+                               check_names=False)
+        tm.assert_series_equal(self.ts / self.ts, self.ts / df['A'],
+                               check_names=False)
 
     def test_operators_combine(self):
         def _check_fill(meth, op, a, b, fill_value=0):

Diff for: pandas/tests/test_groupby.py

@@ -960,10 +960,13 @@ def test_aggregate_item_by_item(self):
 
         # GH5782
         # odd comparisons can result here, so cast to make easy
-        assert_almost_equal(
-            result.xs('foo'), np.array([foo] * K).astype('float64'))
-        assert_almost_equal(
-            result.xs('bar'), np.array([bar] * K).astype('float64'))
+        exp = pd.Series(np.array([foo] * K), index=list('BCD'),
+                        dtype=np.float64, name='foo')
+        tm.assert_series_equal(result.xs('foo'), exp)
+
+        exp = pd.Series(np.array([bar] * K), index=list('BCD'),
+                        dtype=np.float64, name='bar')
+        tm.assert_almost_equal(result.xs('bar'), exp)
 
         def aggfun(ser):
             return ser.size
@@ -1390,7 +1393,8 @@ def test_frame_groupby(self):
         for name, group in grouped:
             mean = group.mean()
             for idx in group.index:
-                assert_almost_equal(transformed.xs(idx), mean)
+                tm.assert_series_equal(transformed.xs(idx), mean,
+                                       check_names=False)
 
         # iterate
         for weekday, group in grouped: