bpo-29981: Update Index for set, dict, and generator 'comprehensions'

Doc/glossary.rst

@@ -304,6 +304,12 @@ Glossary
       keys can be any object with :meth:`__hash__` and :meth:`__eq__` methods.
       Called a hash in Perl.
 
+   dictionary comprehension
+      A compact way to process all or part of the elements in a sequence and
+      return a dictionary with the results. ``results = {n: n ** 2 for n in
+      range(10)}`` generates a dictionary containing key ``n`` which mapped to
+      value ``n ** 2``. See :ref:`comprehensions`.
+
    dictionary view
       The objects returned from :meth:`dict.keys`, :meth:`dict.values`, and
       :meth:`dict.items` are called dictionary views. They provide a dynamic
@@ -1004,6 +1010,12 @@ Glossary
       reserved for rare cases where there are large numbers of instances in a
       memory-critical application.
 
+   set comprehension
+      A compact way to process all or part of the elements in a sequence and
+      return a set with the results. ``results = {c for c in 'abracadabra' if
+      c not in 'abc'}`` generates the set of strings with ``{'r', 'd'}``.  See
+      :ref:`comprehensions`.
+
    sequence
       An :term:`iterable` which supports efficient element access using integer
       indices via the :meth:`__getitem__` special method and defines a

Doc/library/stdtypes.rst

@@ -4114,6 +4114,12 @@ The constructors for both classes work the same:
 .. class:: set([iterable])
            frozenset([iterable])
 
+   Sets can be created by several means:
+
+   * Use a comma-separated list of elements within braces: ``{'jack', 'sjoerd'}``
+   * Use a set comprehension: ``{c for c in 'abracadabra' if c not in 'abc'}``
+   * Use the type constructor: ``set()``, ``set('foobar')``, ``set(['a', 'b', 'foo'])``
+
    Return a new set or frozenset object whose elements are taken from
    *iterable*.  The elements of a set must be :term:`hashable`.  To
    represent sets of sets, the inner sets must be :class:`frozenset`
@@ -4309,6 +4315,14 @@ pairs within braces, for example: ``{'jack': 4098, 'sjoerd': 4127}`` or ``{4098:
            dict(mapping, **kwarg)
            dict(iterable, **kwarg)
 
+   Dictionaries can be created by several means:
+
+   * Use a comma-separated list of ``key: value`` pairs within braces:
+     ``{'jack': 4098, 'sjoerd': 4127}`` or ``{4098: 'jack', 4127: 'sjoerd'}``
+   * Use a dict comprehension: ``{}``, ``{x: x ** 2 for x in range(10)}``
+   * Use the type constructor: ``dict()``,
+     ``dict([('foo', 100), ('bar', 200)])``, ``dict(foo=100, bar=200)``
+
    Return a new dictionary initialized from an optional positional argument
    and a possibly empty set of keyword arguments.
 

Doc/reference/expressions.rst

@@ -162,6 +162,8 @@ ambiguities and allow common typos to pass uncaught.
 Displays for lists, sets and dictionaries
 -----------------------------------------
 
+.. index:: single: comprehensions
+
 For constructing a list, a set or a dictionary Python provides special syntax
 called "displays", each of them in two flavors:
 
@@ -260,6 +262,7 @@ Set displays
 
 .. index::
    pair: set; display
+   pair: set; comprehensions
    object: set
    single: {} (curly brackets); set expression
    single: , (comma); expression list
@@ -287,6 +290,7 @@ Dictionary displays
 
 .. index::
    pair: dictionary; display
+   pair: dictionary; comprehensions
    key, datum, key/datum pair
    object: dictionary
    single: {} (curly brackets); dictionary expression