Author: tim.peters Date: Sat Jun 3 01:22:51 2006 New Revision: 46605 Modified: python/trunk/Doc/lib/libpprint.tex python/trunk/Lib/pprint.py python/trunk/Lib/test/test_pprint.py python/trunk/Misc/NEWS Log: pprint functions used to sort a dict (by key) if and only if the output required more than one line. "Small" dicts got displayed in seemingly random order (the hash-induced order produced by dict.__repr__). None of this was documented. Now pprint functions always sort dicts by key, and the docs promise it. This was proposed and agreed to during the PyCon 2006 core sprint -- I just didn't have time for it before now. Modified: python/trunk/Doc/lib/libpprint.tex ============================================================================== --- python/trunk/Doc/lib/libpprint.tex (original) +++ python/trunk/Doc/lib/libpprint.tex Sat Jun 3 01:22:51 2006 @@ -20,6 +20,10 @@ allowed width. Construct \class{PrettyPrinter} objects explicitly if you need to adjust the width constraint. +\versionchanged[Dictionaries are sorted by key before the display is +computed; before 2.5, a dictionary was sorted only if its display +required more than one line, although that wasn't documented]{2.5} + The \module{pprint} module defines one class: Modified: python/trunk/Lib/pprint.py ============================================================================== --- python/trunk/Lib/pprint.py (original) +++ python/trunk/Lib/pprint.py Sat Jun 3 01:22:51 2006 @@ -246,7 +246,7 @@ append = components.append level += 1 saferepr = _safe_repr - for k, v in object.iteritems(): + for k, v in sorted(object.items()): krepr, kreadable, krecur = saferepr(k, context, maxlevels, level) vrepr, vreadable, vrecur = saferepr(v, context, maxlevels, level) append("%s: %s" % (krepr, vrepr)) Modified: python/trunk/Lib/test/test_pprint.py ============================================================================== --- python/trunk/Lib/test/test_pprint.py (original) +++ python/trunk/Lib/test/test_pprint.py Sat Jun 3 01:22:51 2006 @@ -11,16 +11,21 @@ # list, tuple and dict subclasses that do or don't overwrite __repr__ class list2(list): pass + class list3(list): def __repr__(self): return list.__repr__(self) + class tuple2(tuple): pass + class tuple3(tuple): def __repr__(self): return tuple.__repr__(self) + class dict2(dict): pass + class dict3(dict): def __repr__(self): return dict.__repr__(self) @@ -101,7 +106,13 @@ def test_same_as_repr(self): # Simple objects, small containers and classes that overwrite __repr__ - # For those the result should be the same as repr() + # For those the result should be the same as repr(). + # Ahem. The docs don't say anything about that -- this appears to + # be testing an implementation quirk. Starting in Python 2.5, it's + # not true for dicts: pprint always sorts dicts by key now; before, + # it sorted a dict display if and only if the display required + # multiple lines. For that reason, dicts with more than one element + # aren't tested here. verify = self.assert_ for simple in (0, 0L, 0+0j, 0.0, "", uni(""), (), tuple2(), tuple3(), @@ -112,9 +123,7 @@ (1,2), [3,4], {5: 6, 7: 8}, tuple2((1,2)), tuple3((1,2)), tuple3(range(100)), [3,4], list2([3,4]), list3([3,4]), list3(range(100)), - {5: 6, 7: 8}, dict2({5: 6, 7: 8}), dict3({5: 6, 7: 8}), - dict3([(x,x) for x in range(100)]), - {"xy\tab\n": (3,), 5: [[]], (): {}}, + {5: 6, 7: 8}, dict2({5: 6}), dict3({5: 6}), range(10, -11, -1) ): native = repr(simple) @@ -160,6 +169,24 @@ for type in [list, list2]: self.assertEqual(pprint.pformat(type(o), indent=4), exp) + def test_sorted_dict(self): + # Starting in Python 2.5, pprint sorts dict displays by key regardless + # of how small the dictionary may be. + # Before the change, on 32-bit Windows pformat() gave order + # 'a', 'c', 'b' here, so this test failed. + d = {'a': 1, 'b': 1, 'c': 1} + self.assertEqual(pprint.pformat(d), "{'a': 1, 'b': 1, 'c': 1}") + self.assertEqual(pprint.pformat([d, d]), + "[{'a': 1, 'b': 1, 'c': 1}, {'a': 1, 'b': 1, 'c': 1}]") + + # The next one is kind of goofy. The sorted order depends on the + # alphabetic order of type names: "int" < "str" < "tuple". Before + # Python 2.5, this was in the test_same_as_repr() test. It's worth + # keeping around for now because it's one of few tests of pprint + # against a crazy mix of types. + self.assertEqual(pprint.pformat({"xy\tab\n": (3,), 5: [[]], (): {}}), + r"{5: [[]], 'xy\tab\n': (3,), (): {}}") + def test_subclassing(self): o = {'names with spaces': 'should be presented using repr()', 'others.should.not.be': 'like.this'} Modified: python/trunk/Misc/NEWS ============================================================================== --- python/trunk/Misc/NEWS (original) +++ python/trunk/Misc/NEWS Sat Jun 3 01:22:51 2006 @@ -101,6 +101,12 @@ Library ------- +- The functions in the ``pprint`` module now sort dictionaries by key + before computing the display. Before 2.5, ``pprint`` sorted a dictionary + if and only if its display required more than one line, although that + wasn't documented. The new behavior increases predictability; e.g., + using ``pprint.pprint(a_dict)`` in a doctest is now reliable. + - Patch #1497027: try HTTP digest auth before basic auth in urllib2 (thanks for J. J. Lee).