ENH: Support For Interval __contains__ Other Interval (#46613)

pandas/_libs/interval.pyx

@@ -411,9 +411,11 @@ cdef class Interval(IntervalMixin):
         return hash((self.left, self.right, self.inclusive))
 
     def __contains__(self, key) -> bool:
-        if isinstance(key, Interval):
-            return ((self.left < key.left if self.open_left and key.closed_left else self.left <= key.left) and
-                    (key.right < self.right if self.open_right and key.closed_right else key.right <= self.right))
+        if _interval_like(key):
+            key_closed_left = key.inclusive in ('left', 'both')
+            key_closed_right = key.inclusive in ('right', 'both')
+            return ((self.left < key.left if self.open_left and key_closed_left else self.left <= key.left) and
+                    (key.right < self.right if self.open_right and key_closed_right else key.right <= self.right))
         return ((self.left < key if self.open_left else self.left <= key) and
                 (key < self.right if self.open_right else key <= self.right))
 

pandas/core/indexes/range.py

@@ -135,7 +135,7 @@ def __new__(
 
         # validate the arguments
         if com.all_none(start, stop, step):
-            raise TypeError("RangeIndex(...) must be called with integers")
+            raise TypeError("RangeIndex(...) must be called with integers/floats")
 
         start = ensure_python_int(start) if start is not None else 0