Fix pandas-dev#25068 using the same constant as in numpy for decimal_almost_equal

Author: kinow

pandas/_libs/testing.pyx

@@ -43,7 +43,7 @@ cdef bint decimal_almost_equal(double desired, double actual, int decimal):
     # Code from
     # http://docs.scipy.org/doc/numpy/reference/generated
     # /numpy.testing.assert_almost_equal.html
-    return abs(desired - actual) < (0.5 * 10.0 ** -decimal)
+    return abs(desired - actual) < (1.5 * 10.0 ** -decimal)
 
 
 cpdef assert_dict_equal(a, b, bint compare_keys=True):

pandas/tests/util/test_assert_frame_equal.py

@@ -207,3 +207,11 @@ def test_frame_equal_unicode(df1, df2, msg, by_blocks):
     # when comparing DataFrames containing differing unicode objects.
     with pytest.raises(AssertionError, match=msg):
         assert_frame_equal(df1, df2, by_blocks=by_blocks)
+
+
+def test_frame_equal_precision():
+    # see gh-25068
+    df1 = DataFrame([0.00016, -0.154526, -0.20580199999999998])
+    df2 = DataFrame(
+        [0.00015981824253685772, -0.15452557802200317, -0.20580188930034637])
+    _assert_frame_equal_both(df1, df2, check_exact=False, check_less_precise=3)