Rename duplicate table titles for the Tuple and Set chapters

 * Changed the title of the tables pertaining to operations to end with "Operations" instead of "Methods".
 * Although some chapters refer to these as "Magic Methods" others refer to them as "Operations". I went with the latter.

Author: shadyan

python.rst

@@ -590,7 +590,7 @@ We can access members by position or name (name allows us to be more explicit)::
 
 ..  longtable: format: {>{\hangindent=1em\hangafter=1\raggedright\arraybackslash }p{.3\textwidth} l >{\hangindent=1em\hangafter=1\raggedright\arraybackslash }p{.3\textwidth}}
 
-.. table:: Tuple Methods
+.. table:: Tuple Operations
 
   ================================== ========================= ============================================================
   Operation                          Provided                  Result
@@ -675,7 +675,7 @@ Sets are useful because they provide *set operations*, such as union
 
 ..  longtable: format: {>{\hangindent=1em\hangafter=1\raggedright\arraybackslash }p{.25\textwidth} l >{\hangindent=1em\hangafter=1\raggedright\arraybackslash }p{.35\textwidth}}
 
-.. table:: Set Methods
+.. table:: Set Operations
 
   ======================================= ========================= ============================================================
   Operation                               Provided By               Result