additional review edits

Author: jschendel

pandas/core/indexes/base.py

@@ -200,8 +200,9 @@ def __new__(cls, data=None, dtype=None, copy=False, name=None,
         # interval
         if is_interval_dtype(data) or is_interval_dtype(dtype):
             from .interval import IntervalIndex
+            closed = kwargs.get('closed', None)
             return IntervalIndex(data, dtype=dtype, name=name, copy=copy,
-                                 **kwargs)
+                                 closed=closed)
 
         # index-like
         elif isinstance(data, (np.ndarray, Index, ABCSeries)):

pandas/core/indexes/interval.py

@@ -260,7 +260,7 @@ def _simple_new(cls, left, right, closed=None, name=None, copy=False,
         right = _ensure_index(right, copy=copy)
 
         if dtype is not None:
-            # GH 19262
+            # GH 19262: dtype must be an IntervalDtype to override inferred
             dtype = pandas_dtype(dtype)
             if not is_interval_dtype(dtype):
                 msg = 'dtype must be an IntervalDtype, got {dtype}'
@@ -574,7 +574,7 @@ def from_tuples(cls, data, closed='right', name=None, copy=False,
 
         Examples
         --------
-        >>>  pd.IntervalIndex.from_tuples([(0, 1), (1,2)])
+        >>>  pd.IntervalIndex.from_tuples([(0, 1), (1, 2)])
         IntervalIndex([(0, 1], (1, 2]],
                       closed='right', dtype='interval[int64]')
 
@@ -596,6 +596,7 @@ def from_tuples(cls, data, closed='right', name=None, copy=False,
                 lhs = rhs = np.nan
             else:
                 try:
+                    # need list of length 2 tuples, e.g. [(0, 1), (1, 2), ...]
                     lhs, rhs = d
                 except ValueError:
                     msg = ('IntervalIndex.from_tuples requires tuples of '