FIX printing index with display.max_seq_items=None (GH10182)

Author: jorisvandenbossche

doc/source/whatsnew/v0.16.2.txt

@@ -137,6 +137,7 @@ Bug Fixes
 - Bug in ``Timestamp``'s' ``microsecond``, ``quarter``, ``dayofyear``, ``week`` and ``daysinmonth`` properties return ``np.int`` type, not built-in ``int``. (:issue:`10050`)
 - Bug in ``NaT`` raises ``AttributeError`` when accessing to ``daysinmonth``, ``dayofweek`` properties. (:issue:`10096`)
 
+- Bug in Index repr when using the ``max_seq_items=None`` setting (:issue:`10182`).
 
 - Bug in getting timezone data with ``dateutil`` on various platforms ( :issue:`9059`, :issue:`8639`, :issue:`9663`, :issue:`10121`)
 - Bug in display datetimes with mixed frequencies uniformly; display 'ms' datetimes to the proper precision. (:issue:`10170`)

pandas/core/index.py

@@ -443,7 +443,7 @@ def _format_data(self):
 
         n = len(self)
         sep = ','
-        max_seq_items = get_option('display.max_seq_items')
+        max_seq_items = get_option('display.max_seq_items') or n
         formatter = self._formatter_func
 
         # do we want to justify (only do so for non-objects)
@@ -534,7 +534,7 @@ def _format_attrs(self):
         attrs.append(('dtype',"'%s'" % self.dtype))
         if self.name is not None:
             attrs.append(('name',default_pprint(self.name)))
-        max_seq_items = get_option('display.max_seq_items')
+        max_seq_items = get_option('display.max_seq_items') or len(self)
         if len(self) > max_seq_items:
             attrs.append(('length',len(self)))
         return attrs
@@ -2950,7 +2950,7 @@ def _format_attrs(self):
         if self.name is not None:
             attrs.append(('name',default_pprint(self.name)))
         attrs.append(('dtype',"'%s'" % self.dtype))
-        max_seq_items = get_option('display.max_seq_items')
+        max_seq_items = get_option('display.max_seq_items') or len(self)
         if len(self) > max_seq_items:
             attrs.append(('length',len(self)))
         return attrs

pandas/tests/test_index.py

@@ -133,6 +133,14 @@ def test_str(self):
         self.assertTrue("'foo'" in str(idx))
         self.assertTrue(idx.__class__.__name__ in str(idx))
 
+    def test_repr_max_seq_item_setting(self):
+        # GH10182
+        idx = self.create_index()
+        idx = idx.repeat(50)
+        with pd.option_context("display.max_seq_items", None):
+            repr(idx)
+            self.assertFalse('...' in str(idx))
+
     def test_wrong_number_names(self):
         def testit(ind):
             ind.names = ["apple", "banana", "carrot"]