python: address review comments

The comment about `py_scopes` was simply removed

python/ql/lib/semmle/python/AstExtended.qll

@@ -83,7 +83,7 @@ library class StrListParent extends StrListParent_ { }
 library class ExprParent extends ExprParent_ { }
 
 /** Internal implementation class */
-library class PatternListParent extends PatternListParent_ { }
+class PatternListParent extends PatternListParent_ { }
 
 /** Internal implementation class */
 library class PatternParent extends PatternParent_ { }

python/ql/lib/semmle/python/Patterns.qll

@@ -7,12 +7,7 @@ import python
 /** A pattern in a match statement */
 class Pattern extends Pattern_, AstNode {
   /** Gets the scope of this pattern */
-  override Scope getScope() {
-    // TODO: Should it be defined as
-    //   py_scopes(this, result)
-    // instead?
-    result = this.getCase().getScope()
-  }
+  override Scope getScope() { result = this.getCase().getScope() }
 
   /** Gets the case statement containing this pattern */
   Case getCase() { result.contains(this) }

python/ql/lib/semmle/python/dataflow/new/internal/DataFlowPrivate.qll

@@ -1590,8 +1590,8 @@ import IterableUnpacking
  *  case ('quit' as c) | ('go', ('up'|'down') as c):
  *   ...body
  * ```
- * `command` is the subject of the as-pattern, while the second component of `command` is the subject
- * of the first capture pattern. As such, 'subject' refers to the pattern under evaluation.
+ * `command` is the subject of first the as-pattern, while the second component of `command`
+ * is the subject of the second as-pattern. As such, 'subject' refers to the pattern under evaluation.
  *
  * - as pattern: subject flows to alias as well as to the interior pattern
  * - or pattern: subject flows to each alternative