Remove option to use bare range in init

Author: topper-123

pandas/core/indexes/base.py

@@ -270,8 +270,10 @@ def __new__(cls, data=None, dtype=None, copy=False, name=None,
             data = data.to_numpy()
 
         # range
-        if isinstance(data, (RangeIndex, range)):
+        if isinstance(data, RangeIndex):
             return RangeIndex(start=data, copy=copy, dtype=dtype, name=name)
+        elif isinstance(data, range):
+            return RangeIndex.from_range(data, dtype=dtype, name=name)
 
         # categorical
         elif is_categorical_dtype(data) or is_categorical_dtype(dtype):

pandas/core/indexes/range.py

@@ -40,7 +40,7 @@ class RangeIndex(Int64Index):
 
     Parameters
     ----------
-    start : int (default: 0), range or RangeIndex instance
+    start : int (default: 0), or other RangeIndex instance
         If int and "stop" is not given, interpreted as "stop" instead.
     stop : int (default: 0)
     step : int (default: 1)
@@ -84,11 +84,12 @@ def __new__(cls, start=None, stop=None, step=None,
             if fastpath:
                 return cls._simple_new(range(start, stop, step), name=name)
 
-        # RangeIndex, range
-        if isinstance(start, (RangeIndex, range)):
-            if isinstance(start, RangeIndex):
-                name = start.name if name is None else name
-                start = start._range
+        cls._validate_dtype(dtype)
+
+        # RangeIndex
+        if isinstance(start, RangeIndex):
+            name = start.name if name is None else name
+            start = start._range
             return cls._simple_new(start, dtype=dtype, name=name)
 
         # validate the arguments
@@ -122,14 +123,14 @@ def from_range(cls, data, name=None, dtype=None):
             raise TypeError(
                 '{0}(...) must be called with object coercible to a '
                 'range, {1} was passed'.format(cls.__name__, repr(data)))
+
+        cls._validate_dtype(dtype)
         return cls._simple_new(data, dtype=dtype, name=name)
 
     @classmethod
     def _simple_new(cls, values, name=None, dtype=None, **kwargs):
         result = object.__new__(cls)
 
-        cls._validate_dtype(dtype)
-
         # handle passed None, non-integers
         if values is None:
             # empty

pandas/tests/indexes/test_range.py

@@ -94,9 +94,9 @@ def test_constructor_same(self):
 
     def test_constructor_range(self):
 
-        result = RangeIndex(range(1, 5, 2))
-        expected = RangeIndex(1, 5, 2)
-        tm.assert_index_equal(result, expected, exact=True)
+        msg = "Value needs to be a scalar value, was type <class 'range'>"
+        with pytest.raises(TypeError, match=msg):
+            result = RangeIndex(range(1, 5, 2))
 
         result = RangeIndex.from_range(range(1, 5, 2))
         expected = RangeIndex(1, 5, 2)