small fix

Author: topper-123

pandas/core/indexes/base.py

@@ -2968,7 +2968,7 @@ def union(self, other, sort=None):
             # Now it's:
             # * float | [u]int -> float
             # * uint64 | signed int  -> object
-            # We may change union(float  [u]int) to go to object.
+            # We may change union(float | [u]int) to go to object.
 
             left = self.astype(dtype, copy=False)
             right = other.astype(dtype, copy=False)