Issue #3158: doctest can now find doctests in functions and methods
written in C.
As a part of this, a few doctests have been added to the builtins module
(on hex(), oct(), and bin()), a doctest has been fixed (hopefully on all
platforms) on float, and test_builtins now runs doctests in builtins.
diff --git a/Lib/test/test_doctest.py b/Lib/test/test_doctest.py
index d4ff049..d99a16a 100644
--- a/Lib/test/test_doctest.py
+++ b/Lib/test/test_doctest.py
@@ -644,6 +644,35 @@
>>> test = doctest.DocTestFinder().find(f)[0]
>>> [e.lineno for e in test.examples]
[1, 9, 12]
+
+Finding Doctests in Modules Not Written in Python
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+DocTestFinder can also find doctests in most modules not written in Python.
+We'll use builtins as an example, since it almost certainly isn't written in
+plain ol' Python and is guaranteed to be available.
+
+ >>> import builtins
+ >>> tests = doctest.DocTestFinder().find(builtins)
+ >>> len(tests) # how many objects checked for doctests
+ 794
+ >>> real_tests = [t for t in tests if len(t.examples) > 0]
+ >>> len(real_tests) # how many objects actually have doctests
+ 8
+ >>> for t in real_tests:
+ ... print('{} {}'.format(len(t.examples), t.name))
+ ...
+ 1 builtins.bin
+ 3 builtins.float.as_integer_ratio
+ 2 builtins.float.fromhex
+ 2 builtins.float.hex
+ 1 builtins.hex
+ 1 builtins.int
+ 2 builtins.int.bit_length
+ 1 builtins.oct
+
+Note here that 'bin', 'oct', and 'hex' are functions; 'float.as_integer_ratio',
+'float.hex', and 'int.bit_length' are methods; 'float.fromhex' is a classmethod,
+and 'int' is a type.
"""
def test_DocTestParser(): r"""