A hack to ease compatibility with pre-2.3 Pythons: by default, doctest

now accepts "True" when a test expects "1", and similarly for "False"
versus "0".  This is un-doctest-like, but on balance makes it much
more pleasant to write doctests that pass under 2.2 and 2.3.  I expect
it to go away again, when 2.2 is forgotten.  In the meantime, there's
a new doctest module constant that can be passed to a new optional
argument, if you want to turn this behavior off.

Note that this substitution is very simple-minded:  the expected and
actual outputs have to consist of single tokens.  No attempt is made,
e.g., to accept [True, False] when a test expects [1, 0].  This is a
simple hack for simple tests, and I intend to keep it that way.

1 files changed, 17 insertions, 0 deletions

diff --git a/Doc/lib/libdoctest.tex b/Doc/lib/libdoctest.tex
index 9a795e9..253d6b4 100644
--- a/Doc/lib/libdoctest.tex
+++ b/Doc/lib/libdoctest.tex
@@ -398,6 +398,23 @@ def _test():
     import doctest, sys
     doctest.testmod()
 \end{verbatim}
+
+\item WYSIWYG isn't always the case, starting in Python 2.3.  The
+  string form of boolean results changed from \code{"0"} and
+  \code{"1"} to \code{"False"} and \code{"True"} in Python 2.3.
+  This makes it clumsy to write a doctest showing boolean results that
+  passes under multiple versions of Python.  In Python 2.3, by default,
+  and as a special case, if an expected output block consists solely
+  of \code{"0"} and the actual output block consists solely of
+  \code{"False"}, that's accepted as an exact match, and similarly for
+  \code{"1"} versus \code{"True"}.  This behavior can be turned off by
+  passing the new (in 2.3) module constant
+  \constant{DONT_ACCEPT_TRUE_FOR_1} as the value of \function{testmod()}'s
+  new (in 2.3) optional \var{optionflags} argument.  Some years after
+  the integer spellings of booleans are history, this hack will
+  probably be removed again.
+
+
 \end{enumerate}