revert unrelated changes

Author: XChaitanyaX

Doc/tutorial/datastructures.rst

@@ -444,11 +444,11 @@ packing and sequence unpacking.
 Sets
 ====
 
-Python also includes a data type for *sets* (see :ref:`types-set`). A set is
-an unordered collection with no duplicate elements. Basic uses include
-membership testing and eliminating duplicate entries. Set objects also support
-mathematical operations like union, intersection, difference, and symmetric
-difference.
+Python also includes a data type for *sets* (see :ref:`types-set`).  A set is
+an unordered collection with no duplicate elements.  Basic uses include
+membership testing and eliminating duplicate entries.  Set objects also
+support mathematical operations like union, intersection, difference, and
+symmetric difference.
 
 Curly braces or the :func:`set` function can be used to create sets.  Note: to
 create an empty set you have to use ``set()``, not ``{}``; the latter creates an