diff options
Diffstat (limited to 'Doc/library/doctest.rst')
| -rw-r--r-- | Doc/library/doctest.rst | 133 |
1 files changed, 78 insertions, 55 deletions
diff --git a/Doc/library/doctest.rst b/Doc/library/doctest.rst index b86fef9fd6f..fb43cf918b8 100644 --- a/Doc/library/doctest.rst +++ b/Doc/library/doctest.rst @@ -174,7 +174,7 @@ with assorted summaries at the end. You can force verbose mode by passing ``verbose=True`` to :func:`testmod`, or prohibit it by passing ``verbose=False``. In either of those cases, -``sys.argv`` is not examined by :func:`testmod` (so passing ``-v`` or not +:data:`sys.argv` is not examined by :func:`testmod` (so passing ``-v`` or not has no effect). There is also a command line shortcut for running :func:`testmod`, see section @@ -231,7 +231,7 @@ documentation:: As with :func:`testmod`, :func:`testfile` won't display anything unless an example fails. If an example does fail, then the failing example(s) and the cause(s) of the failure(s) are printed to stdout, using the same format as -:func:`testmod`. +:func:`!testmod`. By default, :func:`testfile` looks for files in the calling module's directory. See section :ref:`doctest-basic-api` for a description of the optional arguments @@ -311,6 +311,9 @@ Which Docstrings Are Examined? The module docstring, and all function, class and method docstrings are searched. Objects imported into the module are not searched. +.. attribute:: module.__test__ + :no-typesetting: + In addition, there are cases when you want tests to be part of a module but not part of the help text, which requires that the tests not be included in the docstring. Doctest looks for a module-level variable called ``__test__`` and uses it to locate other @@ -533,7 +536,7 @@ Some details you should read once, but won't need to remember: * The interactive shell omits the traceback header line for some :exc:`SyntaxError`\ s. But doctest uses the traceback header line to distinguish exceptions from non-exceptions. So in the rare case where you need - to test a :exc:`SyntaxError` that omits the traceback header, you will need to + to test a :exc:`!SyntaxError` that omits the traceback header, you will need to manually add the traceback header line to your test example. .. index:: single: ^ (caret); marker @@ -860,15 +863,15 @@ The :const:`ELLIPSIS` directive gives a nice approach for the last example: <C object at 0x...> Floating-point numbers are also subject to small output variations across -platforms, because Python defers to the platform C library for float formatting, -and C libraries vary widely in quality here. :: +platforms, because Python defers to the platform C library for some +floating-point calculations, and C libraries vary widely in quality here. :: - >>> 1./7 # risky - 0.14285714285714285 - >>> print(1./7) # safer - 0.142857142857 - >>> print(round(1./7, 6)) # much safer - 0.142857 + >>> 1000**0.1 # risky + 1.9952623149688797 + >>> round(1000**0.1, 9) # safer + 1.995262315 + >>> print(f'{1000**0.1:.4f}') # much safer + 1.9953 Numbers of the form ``I/2.**J`` are safe across all platforms, and I often contrive doctest examples to produce numbers of that form:: @@ -938,13 +941,13 @@ and :ref:`doctest-simple-testfile`. Optional argument *verbose* prints lots of stuff if true, and prints only failures if false; by default, or if ``None``, it's true if and only if ``'-v'`` - is in ``sys.argv``. + is in :data:`sys.argv`. Optional argument *report* prints a summary at the end when true, else prints nothing at the end. In verbose mode, the summary is detailed, else the summary is very brief (in fact, empty if all tests passed). - Optional argument *optionflags* (default value 0) takes the + Optional argument *optionflags* (default value ``0``) takes the :ref:`bitwise OR <bitwise>` of option flags. See section :ref:`doctest-options`. @@ -1043,12 +1046,15 @@ from text files and modules with doctests: Convert doctest tests from one or more text files to a :class:`unittest.TestSuite`. - The returned :class:`unittest.TestSuite` is to be run by the unittest framework - and runs the interactive examples in each file. If an example in any file - fails, then the synthesized unit test fails, and a :exc:`failureException` - exception is raised showing the name of the file containing the test and a - (sometimes approximate) line number. If all the examples in a file are - skipped, then the synthesized unit test is also marked as skipped. + The returned :class:`unittest.TestSuite` is to be run by the unittest + framework and runs the interactive examples in each file. + Each file is run as a separate unit test, and each example in a file + is run as a :ref:`subtest <subtests>`. + If any example in a file fails, then the synthesized unit test fails. + The traceback for failure or error contains the name of the file + containing the test and a (sometimes approximate) line number. + If all the examples in a file are skipped, then the synthesized unit + test is also marked as skipped. Pass one or more paths (as strings) to text files to be examined. @@ -1078,13 +1084,14 @@ from text files and modules with doctests: Optional argument *setUp* specifies a set-up function for the test suite. This is called before running the tests in each file. The *setUp* function - will be passed a :class:`DocTest` object. The setUp function can access the - test globals as the *globs* attribute of the test passed. + will be passed a :class:`DocTest` object. The *setUp* function can access the + test globals as the :attr:`~DocTest.globs` attribute of the test passed. Optional argument *tearDown* specifies a tear-down function for the test suite. This is called after running the tests in each file. The *tearDown* - function will be passed a :class:`DocTest` object. The setUp function can - access the test globals as the *globs* attribute of the test passed. + function will be passed a :class:`DocTest` object. The *tearDown* function can + access the test globals as the :attr:`~DocTest.globs` attribute of the test + passed. Optional argument *globs* is a dictionary containing the initial global variables for the tests. A new copy of this dictionary is created for each @@ -1105,16 +1112,22 @@ from text files and modules with doctests: The global ``__file__`` is added to the globals provided to doctests loaded from a text file using :func:`DocFileSuite`. + .. versionchanged:: next + Run each example as a :ref:`subtest <subtests>`. + .. function:: DocTestSuite(module=None, globs=None, extraglobs=None, test_finder=None, setUp=None, tearDown=None, optionflags=0, checker=None) Convert doctest tests for a module to a :class:`unittest.TestSuite`. - The returned :class:`unittest.TestSuite` is to be run by the unittest framework - and runs each doctest in the module. If any of the doctests fail, then the - synthesized unit test fails, and a :exc:`failureException` exception is raised - showing the name of the file containing the test and a (sometimes approximate) - line number. If all the examples in a docstring are skipped, then the + The returned :class:`unittest.TestSuite` is to be run by the unittest + framework and runs each doctest in the module. + Each docstring is run as a separate unit test, and each example in + a docstring is run as a :ref:`subtest <subtests>`. + If any of the doctests fail, then the synthesized unit test fails. + The traceback for failure or error contains the name of the file + containing the test and a (sometimes approximate) line number. + If all the examples in a docstring are skipped, then the synthesized unit test is also marked as skipped. Optional argument *module* provides the module to be tested. It can be a module @@ -1123,7 +1136,7 @@ from text files and modules with doctests: Optional argument *globs* is a dictionary containing the initial global variables for the tests. A new copy of this dictionary is created for each - test. By default, *globs* is a new empty dictionary. + test. By default, *globs* is the module's :attr:`~module.__dict__`. Optional argument *extraglobs* specifies an extra set of global variables, which is merged into *globs*. By default, no extra globals are used. @@ -1132,7 +1145,7 @@ from text files and modules with doctests: drop-in replacement) that is used to extract doctests from the module. Optional arguments *setUp*, *tearDown*, and *optionflags* are the same as for - function :func:`DocFileSuite` above. + function :func:`DocFileSuite` above, but they are called for each docstring. This function uses the same search technique as :func:`testmod`. @@ -1140,11 +1153,8 @@ from text files and modules with doctests: :func:`DocTestSuite` returns an empty :class:`unittest.TestSuite` if *module* contains no docstrings instead of raising :exc:`ValueError`. -.. exception:: failureException - - When doctests which have been converted to unit tests by :func:`DocFileSuite` - or :func:`DocTestSuite` fail, this exception is raised showing the name of - the file containing the test and a (sometimes approximate) line number. + .. versionchanged:: next + Run each example as a :ref:`subtest <subtests>`. Under the covers, :func:`DocTestSuite` creates a :class:`unittest.TestSuite` out of :class:`!doctest.DocTestCase` instances, and :class:`!DocTestCase` is a @@ -1158,15 +1168,15 @@ of :class:`!DocTestCase`. So both ways of creating a :class:`unittest.TestSuite` run instances of :class:`!DocTestCase`. This is important for a subtle reason: when you run -:mod:`doctest` functions yourself, you can control the :mod:`doctest` options in -use directly, by passing option flags to :mod:`doctest` functions. However, if -you're writing a :mod:`unittest` framework, :mod:`unittest` ultimately controls +:mod:`doctest` functions yourself, you can control the :mod:`!doctest` options in +use directly, by passing option flags to :mod:`!doctest` functions. However, if +you're writing a :mod:`unittest` framework, :mod:`!unittest` ultimately controls when and how tests get run. The framework author typically wants to control -:mod:`doctest` reporting options (perhaps, e.g., specified by command line -options), but there's no way to pass options through :mod:`unittest` to -:mod:`doctest` test runners. +:mod:`!doctest` reporting options (perhaps, e.g., specified by command line +options), but there's no way to pass options through :mod:`!unittest` to +:mod:`!doctest` test runners. -For this reason, :mod:`doctest` also supports a notion of :mod:`doctest` +For this reason, :mod:`doctest` also supports a notion of :mod:`!doctest` reporting flags specific to :mod:`unittest` support, via this function: @@ -1181,12 +1191,12 @@ reporting flags specific to :mod:`unittest` support, via this function: :mod:`unittest`: the :meth:`!runTest` method of :class:`!DocTestCase` looks at the option flags specified for the test case when the :class:`!DocTestCase` instance was constructed. If no reporting flags were specified (which is the - typical and expected case), :mod:`!doctest`'s :mod:`unittest` reporting flags are + typical and expected case), :mod:`!doctest`'s :mod:`!unittest` reporting flags are :ref:`bitwise ORed <bitwise>` into the option flags, and the option flags so augmented are passed to the :class:`DocTestRunner` instance created to run the doctest. If any reporting flags were specified when the :class:`!DocTestCase` instance was constructed, :mod:`!doctest`'s - :mod:`unittest` reporting flags are ignored. + :mod:`!unittest` reporting flags are ignored. The value of the :mod:`unittest` reporting flags in effect before the function was called is returned by the function. @@ -1279,7 +1289,7 @@ DocTest Objects .. attribute:: filename The name of the file that this :class:`DocTest` was extracted from; or - ``None`` if the filename is unknown, or if the :class:`DocTest` was not + ``None`` if the filename is unknown, or if the :class:`!DocTest` was not extracted from a file. @@ -1419,10 +1429,10 @@ DocTestFinder objects The globals for each :class:`DocTest` is formed by combining *globs* and *extraglobs* (bindings in *extraglobs* override bindings in *globs*). A new - shallow copy of the globals dictionary is created for each :class:`DocTest`. - If *globs* is not specified, then it defaults to the module's *__dict__*, if - specified, or ``{}`` otherwise. If *extraglobs* is not specified, then it - defaults to ``{}``. + shallow copy of the globals dictionary is created for each :class:`!DocTest`. + If *globs* is not specified, then it defaults to the module's + :attr:`~module.__dict__`, if specified, or ``{}`` otherwise. + If *extraglobs* is not specified, then it defaults to ``{}``. .. _doctest-doctestparser: @@ -1446,7 +1456,7 @@ DocTestParser objects :class:`DocTest` object. *globs*, *name*, *filename*, and *lineno* are attributes for the new - :class:`DocTest` object. See the documentation for :class:`DocTest` for more + :class:`!DocTest` object. See the documentation for :class:`DocTest` for more information. @@ -1461,7 +1471,7 @@ DocTestParser objects Divide the given string into examples and intervening text, and return them as a list of alternating :class:`Example`\ s and strings. Line numbers for the - :class:`Example`\ s are 0-based. The optional argument *name* is a name + :class:`!Example`\ s are 0-based. The optional argument *name* is a name identifying this string, and is only used for error messages. @@ -1501,14 +1511,14 @@ DocTestRunner objects :class:`OutputChecker`. This comparison may be customized with a number of option flags; see section :ref:`doctest-options` for more information. If the option flags are insufficient, then the comparison may also be customized by - passing a subclass of :class:`OutputChecker` to the constructor. + passing a subclass of :class:`!OutputChecker` to the constructor. The test runner's display output can be controlled in two ways. First, an output function can be passed to :meth:`run`; this function will be called with strings that should be displayed. It defaults to ``sys.stdout.write``. If capturing the output is not sufficient, then the display output can be also customized by subclassing DocTestRunner, and overriding the methods - :meth:`report_start`, :meth:`report_success`, + :meth:`report_skip`, :meth:`report_start`, :meth:`report_success`, :meth:`report_unexpected_exception`, and :meth:`report_failure`. The optional keyword argument *checker* specifies the :class:`OutputChecker` @@ -1533,6 +1543,19 @@ DocTestRunner objects :class:`DocTestRunner` defines the following methods: + .. method:: report_skip(out, test, example) + + Report that the given example was skipped. This method is provided to + allow subclasses of :class:`DocTestRunner` to customize their output; it + should not be called directly. + + *example* is the example about to be processed. *test* is the test + containing *example*. *out* is the output function that was passed to + :meth:`DocTestRunner.run`. + + .. versionadded:: next + + .. method:: report_start(out, test, example) Report that the test runner is about to process the given example. This method @@ -1540,7 +1563,7 @@ DocTestRunner objects output; it should not be called directly. *example* is the example about to be processed. *test* is the test - *containing example*. *out* is the output function that was passed to + containing *example*. *out* is the output function that was passed to :meth:`DocTestRunner.run`. @@ -1940,7 +1963,7 @@ several options for organizing tests: containing test cases for the named topics. These functions can be included in the same file as the module, or separated out into a separate test file. -* Define a ``__test__`` dictionary mapping from regression test topics to +* Define a :attr:`~module.__test__` dictionary mapping from regression test topics to docstrings containing test cases. When you have placed your tests in a module, the module can itself be the test |