Merge pull request #10959 from takluyver/i10950

Defining __repr__ should override pretty printer for parent class

IPython/core/tests/test_formatters.py

@@ -49,7 +49,7 b' def test_pretty():'
     f = PlainTextFormatter()
     f.for_type(A, foo_printer)
     nt.assert_equal(f(A()), 'foo')
-    nt.assert_equal(f(B()), 'foo')
+    nt.assert_equal(f(B()), 'B()')
     nt.assert_equal(f(GoodPretty()), 'foo')
     # Just don't raise an exception for the following:
     f(BadPretty())

IPython/lib/pretty.py

@@ -395,6 +395,10 b' class RepresentationPrinter(PrettyPrinter):'
                             meth = cls._repr_pretty_
                             if callable(meth):
                                 return meth(obj, self, cycle)
+                        if cls is not object \
+                                and callable(cls.__dict__.get('__repr__')):
+                            return _repr_pprint(obj, self, cycle)
+
             return _default_pprint(obj, self, cycle)
         finally:
             self.end_group()
@@ -540,17 +544,12 b' def _default_pprint(obj, p, cycle):'
     p.end_group(1, '>')
 
 
-def _seq_pprinter_factory(start, end, basetype):
+def _seq_pprinter_factory(start, end):
     """
     Factory that returns a pprint function useful for sequences.  Used by
     the default pprint for tuples, dicts, and lists.
     """
     def inner(obj, p, cycle):
-        typ = type(obj)
-        if basetype is not None and typ is not basetype and typ.__repr__ != basetype.__repr__:
-            # If the subclass provides its own repr, use it instead.
-            return p.text(typ.__repr__(obj))
-
         if cycle:
             return p.text(start + '...' + end)
         step = len(start)
@@ -567,21 +566,16 b' def _seq_pprinter_factory(start, end, basetype):'
     return inner
 
 
-def _set_pprinter_factory(start, end, basetype):
+def _set_pprinter_factory(start, end):
     """
     Factory that returns a pprint function useful for sets and frozensets.
     """
     def inner(obj, p, cycle):
-        typ = type(obj)
-        if basetype is not None and typ is not basetype and typ.__repr__ != basetype.__repr__:
-            # If the subclass provides its own repr, use it instead.
-            return p.text(typ.__repr__(obj))
-
         if cycle:
             return p.text(start + '...' + end)
         if len(obj) == 0:
             # Special case.
-            p.text(basetype.__name__ + '()')
+            p.text(type(obj).__name__ + '()')
         else:
             step = len(start)
             p.begin_group(step, start)
@@ -599,17 +593,12 b' def _set_pprinter_factory(start, end, basetype):'
     return inner
 
 
-def _dict_pprinter_factory(start, end, basetype=None):
+def _dict_pprinter_factory(start, end):
     """
     Factory that returns a pprint function used by the default pprint of
     dicts and dict proxies.
     """
     def inner(obj, p, cycle):
-        typ = type(obj)
-        if basetype is not None and typ is not basetype and typ.__repr__ != basetype.__repr__:
-            # If the subclass provides its own repr, use it instead.
-            return p.text(typ.__repr__(obj))
-
         if cycle:
             return p.text('{...}')
         step = len(start)
@@ -750,12 +739,12 b' _type_pprinters = {'
     int:                        _repr_pprint,
     float:                      _repr_pprint,
     str:                        _repr_pprint,
-    tuple:                      _seq_pprinter_factory('(', ')', tuple),
-    list:                       _seq_pprinter_factory('[', ']', list),
-    dict:                       _dict_pprinter_factory('{', '}', dict),
+    tuple:                      _seq_pprinter_factory('(', ')'),
+    list:                       _seq_pprinter_factory('[', ']'),
+    dict:                       _dict_pprinter_factory('{', '}'),
     
-    set:                        _set_pprinter_factory('{', '}', set),
-    frozenset:                  _set_pprinter_factory('frozenset({', '})', frozenset),
+    set:                        _set_pprinter_factory('{', '}'),
+    frozenset:                  _set_pprinter_factory('frozenset({', '})'),
     super:                      _super_pprint,
     _re_pattern_type:           _re_pattern_pprint,
     type:                       _type_pprint,

IPython/lib/tests/test_pretty.py

@@ -420,4 +420,24 b' def test_function_pretty():'
         return "Don't panic"
 
     nt.assert_in('meaning_of_life(question=None)', pretty.pretty(meaning_of_life))
-    
+
+
+class OrderedCounter(Counter, OrderedDict):
+    'Counter that remembers the order elements are first encountered'
+
+    def __repr__(self):
+        return '%s(%r)' % (self.__class__.__name__, OrderedDict(self))
+
+    def __reduce__(self):
+        return self.__class__, (OrderedDict(self),)
+
+class MySet(set):  # Override repr of a basic type
+    def __repr__(self):
+        return 'mine'
+
+def test_custom_repr():
+    """A custom repr should override a pretty printer for a parent type"""
+    oc = OrderedCounter("abracadabra")
+    nt.assert_in("OrderedCounter(OrderedDict", pretty.pretty(oc))
+
+    nt.assert_equal(pretty.pretty(MySet()), 'mine')