diff options
| -rw-r--r-- | Doc/library/pprint.rst | 40 | ||||
| -rw-r--r-- | Lib/pprint.py | 5 | ||||
| -rw-r--r-- | Lib/test/test_pprint.py | 8 | ||||
| -rw-r--r-- | Misc/NEWS.d/next/Library/2021-06-20-14-03-18.bpo-41546.lO1jXU.rst | 1 |
4 files changed, 26 insertions, 28 deletions
diff --git a/Doc/library/pprint.rst b/Doc/library/pprint.rst index 8f37450..3da5aa9 100644 --- a/Doc/library/pprint.rst +++ b/Doc/library/pprint.rst @@ -46,6 +46,8 @@ The :mod:`pprint` module defines one class: *stream* (default ``sys.stdout``) is a :term:`file-like object` to which the output will be written by calling its :meth:`write` method. + If both *stream* and ``sys.stdout`` are ``None``, then + :meth:`~PrettyPrinter.pprint` silently returns. Other values configure the manner in which nesting of complex data structures is displayed. @@ -84,6 +86,9 @@ The :mod:`pprint` module defines one class: .. versionchanged:: 3.10 Added the *underscore_numbers* parameter. + .. versionchanged:: 3.11 + No longer attempts to write to ``sys.stdout`` if it is ``None``. + >>> import pprint >>> stuff = ['spam', 'eggs', 'lumberjack', 'knights', 'ni'] >>> stuff.insert(0, stuff[:]) @@ -107,24 +112,13 @@ The :mod:`pprint` module defines one class: >>> pp.pprint(tup) ('spam', ('eggs', ('lumberjack', ('knights', ('ni', ('dead', (...))))))) - -The :mod:`pprint` module also provides several shortcut functions: - .. function:: pformat(object, indent=1, width=80, depth=None, *, \ compact=False, sort_dicts=True, underscore_numbers=False) Return the formatted representation of *object* as a string. *indent*, - *width*, *depth*, *compact*, *sort_dicts* and *underscore_numbers* will be passed to the - :class:`PrettyPrinter` constructor as formatting parameters. - - .. versionchanged:: 3.4 - Added the *compact* parameter. - - .. versionchanged:: 3.8 - Added the *sort_dicts* parameter. - - .. versionchanged:: 3.10 - Added the *underscore_numbers* parameter. + *width*, *depth*, *compact*, *sort_dicts* and *underscore_numbers* are + passed to the :class:`PrettyPrinter` constructor as formatting parameters + and their meanings are as described in its documentation above. .. function:: pp(object, *args, sort_dicts=False, **kwargs) @@ -142,20 +136,15 @@ The :mod:`pprint` module also provides several shortcut functions: compact=False, sort_dicts=True, underscore_numbers=False) Prints the formatted representation of *object* on *stream*, followed by a - newline. If *stream* is ``None``, ``sys.stdout`` is used. This may be used + newline. If *stream* is ``None``, ``sys.stdout`` is used. This may be used in the interactive interpreter instead of the :func:`print` function for inspecting values (you can even reassign ``print = pprint.pprint`` for use - within a scope). *indent*, *width*, *depth*, *compact*, *sort_dicts* and *underscore_numbers* will - be passed to the :class:`PrettyPrinter` constructor as formatting parameters. - - .. versionchanged:: 3.4 - Added the *compact* parameter. - - .. versionchanged:: 3.8 - Added the *sort_dicts* parameter. + within a scope). - .. versionchanged:: 3.10 - Added the *underscore_numbers* parameter. + The configuration parameters *stream*, *indent*, *width*, *depth*, + *compact*, *sort_dicts* and *underscore_numbers* are passed to the + :class:`PrettyPrinter` constructor and their meanings are as + described in its documentation above. >>> import pprint >>> stuff = ['spam', 'eggs', 'lumberjack', 'knights', 'ni'] @@ -168,7 +157,6 @@ The :mod:`pprint` module also provides several shortcut functions: 'knights', 'ni'] - .. function:: isreadable(object) .. index:: builtin: eval diff --git a/Lib/pprint.py b/Lib/pprint.py index 13819f3..60ce57e 100644 --- a/Lib/pprint.py +++ b/Lib/pprint.py @@ -148,8 +148,9 @@ class PrettyPrinter: self._underscore_numbers = underscore_numbers def pprint(self, object): - self._format(object, self._stream, 0, 0, {}, 0) - self._stream.write("\n") + if self._stream is not None: + self._format(object, self._stream, 0, 0, {}, 0) + self._stream.write("\n") def pformat(self, object): sio = _StringIO() diff --git a/Lib/test/test_pprint.py b/Lib/test/test_pprint.py index 6c714fd..c7b9893 100644 --- a/Lib/test/test_pprint.py +++ b/Lib/test/test_pprint.py @@ -1,6 +1,7 @@ # -*- coding: utf-8 -*- import collections +import contextlib import dataclasses import io import itertools @@ -159,6 +160,13 @@ class QueryTestCase(unittest.TestCase): self.assertTrue(pp.isreadable(safe), "expected isreadable for %r" % (safe,)) + def test_stdout_is_None(self): + with contextlib.redirect_stdout(None): + # smoke test - there is no output to check + value = 'this should not fail' + pprint.pprint(value) + pprint.PrettyPrinter().pprint(value) + def test_knotted(self): # Verify .isrecursive() and .isreadable() w/ recursion # Tie a knot. diff --git a/Misc/NEWS.d/next/Library/2021-06-20-14-03-18.bpo-41546.lO1jXU.rst b/Misc/NEWS.d/next/Library/2021-06-20-14-03-18.bpo-41546.lO1jXU.rst new file mode 100644 index 0000000..050da76 --- /dev/null +++ b/Misc/NEWS.d/next/Library/2021-06-20-14-03-18.bpo-41546.lO1jXU.rst @@ -0,0 +1 @@ +Make :mod:`pprint` (like the builtin ``print``) not attempt to write to ``stdout`` when it is ``None``. |