From 5130eaed1113f9c0cf99c001fb090901d19a1045 Mon Sep 17 00:00:00 2001 From: Guido van Rossum Date: Mon, 15 Aug 2016 15:06:38 -0700 Subject: Add docs for typing.AnyStr and typing.Text. By Michael Lee. --- Doc/library/typing.rst | 27 +++++++++++++++++++++++++++ 1 file changed, 27 insertions(+) (limited to 'Doc/library/typing.rst') diff --git a/Doc/library/typing.rst b/Doc/library/typing.rst index c982a7fae1..bc71e1e840 100644 --- a/Doc/library/typing.rst +++ b/Doc/library/typing.rst @@ -647,6 +647,33 @@ The module defines the following classes, functions and decorators: yield start start += 1 +.. class:: AnyStr + + ``AnyStr`` is a type variable defined as + ``AnyStr = TypeVar('AnyStr', str, bytes)``. + + 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:: + + def concat(a: AnyStr, b: AnyStr) -> AnyStr: + return a + b + + concat(u"foo", u"bar") # Ok, output has type 'unicode' + concat(b"foo", b"bar") # Ok, output has type 'bytes' + concat(u"foo", b"bar") # Error, cannot mix unicode and bytes + +.. class:: Text + + ``Text`` is an alias for ``str``. It is provided to supply a forward + compatible path for Python 2 code: in Python 2, ``Text`` is an alias for + ``unicode``. + + Use ``Text`` to indicate that a value must contain a unicode string in + a manner that is compatible with both Python 2 and Python 3:: + + def add_unicode_checkmark(text: Text) -> Text: + return text + u' \u2713' + .. class:: io Wrapper namespace for I/O stream types. -- cgit v1.2.1