python
diff --git a/‎library/typing.po‎
Lines changed: 25 additions & 19 deletions b/‎library/typing.po‎
Lines changed: 25 additions & 19 deletions
@@ -8,7 +8,7 @@ msgid ""
 msgstr ""
 "Project-Id-Version: Python 3.7\n"
 "Report-Msgid-Bugs-To: \n"
-"POT-Creation-Date: 2018-06-30 05:56+0900\n"
+"POT-Creation-Date: 2018-08-06 08:47+0900\n"
 "PO-Revision-Date: YEAR-MO-DA HO:MI+ZONE\n"
 "Last-Translator: ww song <[email protected]>, 2018\n"
 "Language-Team: Chinese (China) (https://www.transifex.com/python-doc/teams/5390/zh_CN/)\n"
@@ -910,44 +910,50 @@ msgstr ""
 #: ../../library/typing.rst:991
 msgid ""
 "Note that this is not the same concept as an optional argument, which is one"
-" that has a default.  An optional argument with a default needn't use the "
-"``Optional`` qualifier on its type annotation (although it is inferred if "
-"the default is ``None``). A mandatory argument may still have an "
-"``Optional`` type if an explicit value of ``None`` is allowed."
+" that has a default.  An optional argument with a default does not require "
+"the ``Optional`` qualifier on its type annotation just because it is "
+"optional. For example::"
 msgstr ""
 
-#: ../../library/typing.rst:1000
+#: ../../library/typing.rst:999
+msgid ""
+"On the other hand, if an explicit value of ``None`` is allowed, the use of "
+"``Optional`` is appropriate, whether the argument is optional or not. For "
+"example::"
+msgstr ""
+
+#: ../../library/typing.rst:1008
 msgid ""
 "Tuple type; ``Tuple[X, Y]`` is the type of a tuple of two items with the "
 "first item of type X and the second of type Y."
 msgstr ""
 
-#: ../../library/typing.rst:1003
+#: ../../library/typing.rst:1011
 msgid ""
 "Example: ``Tuple[T1, T2]`` is a tuple of two elements corresponding to type "
 "variables T1 and T2.  ``Tuple[int, float, str]`` is a tuple of an int, a "
 "float and a string."
 msgstr ""
 
-#: ../../library/typing.rst:1007
+#: ../../library/typing.rst:1015
 msgid ""
 "To specify a variable-length tuple of homogeneous type, use literal "
 "ellipsis, e.g. ``Tuple[int, ...]``. A plain :data:`Tuple` is equivalent to "
 "``Tuple[Any, ...]``, and in turn to :class:`tuple`."
 msgstr ""
 
-#: ../../library/typing.rst:1013
+#: ../../library/typing.rst:1021
 msgid "Callable type; ``Callable[[int], str]`` is a function of (int) -> str."
 msgstr ""
 
-#: ../../library/typing.rst:1015
+#: ../../library/typing.rst:1023
 msgid ""
 "The subscription syntax must always be used with exactly two values: the "
 "argument list and the return type.  The argument list must be a list of "
 "types or an ellipsis; the return type must be a single type."
 msgstr ""
 
-#: ../../library/typing.rst:1020
+#: ../../library/typing.rst:1028
 msgid ""
 "There is no syntax to indicate optional or keyword arguments; such function "
 "types are rarely used as callback types. ``Callable[..., ReturnType]`` "
@@ -957,48 +963,48 @@ msgid ""
 ":class:`collections.abc.Callable`."
 msgstr ""
 
-#: ../../library/typing.rst:1030
+#: ../../library/typing.rst:1038
 msgid "Special type construct to mark class variables."
 msgstr ""
 
-#: ../../library/typing.rst:1032
+#: ../../library/typing.rst:1040
 msgid ""
 "As introduced in :pep:`526`, a variable annotation wrapped in ClassVar "
 "indicates that a given attribute is intended to be used as a class variable "
 "and should not be set on instances of that class. Usage::"
 msgstr ""
 
-#: ../../library/typing.rst:1040
+#: ../../library/typing.rst:1048
 msgid ":data:`ClassVar` accepts only types and cannot be further subscribed."
 msgstr ""
 
-#: ../../library/typing.rst:1042
+#: ../../library/typing.rst:1050
 msgid ""
 ":data:`ClassVar` is not a class itself, and should not be used with "
 ":func:`isinstance` or :func:`issubclass`. :data:`ClassVar` does not change "
 "Python runtime behavior, but it can be used by third-party type checkers. "
 "For example, a type checker might flag the following code as an error::"
 msgstr ""
 
-#: ../../library/typing.rst:1056
+#: ../../library/typing.rst:1064
 msgid ""
 "``AnyStr`` is a type variable defined as ``AnyStr = TypeVar('AnyStr', str, "
 "bytes)``."
 msgstr ""
 
-#: ../../library/typing.rst:1059
+#: ../../library/typing.rst:1067
 msgid ""
 "It is meant to be used for functions that may accept any kind of string "
 "without allowing different kinds of strings to mix. For example::"
 msgstr ""
 
-#: ../../library/typing.rst:1071
+#: ../../library/typing.rst:1079
 msgid ""
 "A special constant that is assumed to be ``True`` by 3rd party static type "
 "checkers. It is ``False`` at runtime. Usage::"
 msgstr ""
 
-#: ../../library/typing.rst:1080
+#: ../../library/typing.rst:1088
 msgid ""
 "Note that the first type annotation must be enclosed in quotes, making it a "
 "\"forward reference\", to hide the ``expensive_mod`` reference from the "