Incorporate Skip's suggestion to use SciPy's validation test near
equality. Note, there is another flavor that compares to a given
number of significant digits rather than decimal places. If there
is a demand, that could be added at a later date.
diff --git a/Doc/lib/libunittest.tex b/Doc/lib/libunittest.tex
index b1c0918..2d710e8 100644
--- a/Doc/lib/libunittest.tex
+++ b/Doc/lib/libunittest.tex
@@ -501,6 +501,30 @@
\var{second}.
\end{methoddesc}
+\begin{methoddesc}[TestCase]{assertAlmostEqual}{first, second\optional{,
+ places\optional{, msg}}}
+\methodline{failUnlessAlmostEqual}{first, second\optional{,
+ places\optional{, msg}}}
+ Test that \var{first} and \var{second} are approximately equal
+ by computing the difference, rounding to the given number of \var{places},
+ and comparing to zero. Note that comparing a given number of decimal places
+ is not the same as comparing a given number of significant digits.
+ If the values do not compare equal, the test will fail with the explanation
+ given by \var{msg}, or \code{None}.
+\end{methoddesc}
+
+\begin{methoddesc}[TestCase]{assertNotAlmostEqual}{first, second\optional{,
+ places\optional{, msg}}}
+\methodline{failIfAlmostEqual}{first, second\optional{,
+ places\optional{, msg}}}
+ Test that \var{first} and \var{second} are not approximately equal
+ by computing the difference, rounding to the given number of \var{places},
+ and comparing to zero. Note that comparing a given number of decimal places
+ is not the same as comparing a given number of significant digits.
+ If the values do not compare equal, the test will fail with the explanation
+ given by \var{msg}, or \code{None}.
+\end{methoddesc}
+
\begin{methoddesc}[TestCase]{assertRaises}{exception, callable, \moreargs}
\methodline{failUnlessRaises}{exception, callable, \moreargs}
Test that an exception is raised when \var{callable} is called with
diff --git a/Lib/unittest.py b/Lib/unittest.py
index 9100a78..31d9cb4 100644
--- a/Lib/unittest.py
+++ b/Lib/unittest.py
@@ -300,10 +300,38 @@
raise self.failureException, \
(msg or '%s == %s' % (`first`, `second`))
+ def failUnlessAlmostEqual(self, first, second, places=7, msg=None):
+ """Fail if the two objects are unequal as determined by their
+ difference rounded to the given number of decimal places
+ (default 7) and comparing to zero.
+
+ Note that decimal places (from zero) is usually not the same
+ as significant digits (measured from the most signficant digit).
+ """
+ if round(second-first, places) != 0:
+ raise self.failureException, \
+ (msg or '%s != %s within %s places' % (`first`, `second`, `places` ))
+
+ def failIfAlmostEqual(self, first, second, places=7, msg=None):
+ """Fail if the two objects are equal as determined by their
+ difference rounded to the given number of decimal places
+ (default 7) and comparing to zero.
+
+ Note that decimal places (from zero) is usually not the same
+ as significant digits (measured from the most signficant digit).
+ """
+ if round(second-first, places) == 0:
+ raise self.failureException, \
+ (msg or '%s == %s within %s places' % (`first`, `second`, `places`))
+
assertEqual = assertEquals = failUnlessEqual
assertNotEqual = assertNotEquals = failIfEqual
+ assertAlmostEqual = assertAlmostEquals = failUnlessAlmostEqual
+
+ assertNotAlmostEqual = assertNotAlmostEquals = failIfAlmostEqual
+
assertRaises = failUnlessRaises
assert_ = failUnless