From ab86521a9d9999731e39bd9056420bb7774fd144 Mon Sep 17 00:00:00 2001
From: Marcin Niemira <marcin.niemira@gmail.com>
Date: Mon, 22 Apr 2019 21:13:51 +1000
Subject: [PATCH] bpo-36523: Add docstring to io.IOBase.writelines (GH-12683)

---
 Lib/_pyio.py                                              | 5 +++++
 .../2019-04-04-19-11-47.bpo-36523.sG1Tr4.rst              | 1 +
 Modules/_io/clinic/iobase.c.h                             | 8 ++++++--
 Modules/_io/iobase.c                                      | 7 ++++++-
 4 files changed, 18 insertions(+), 3 deletions(-)
 create mode 100644 Misc/NEWS.d/next/Documentation/2019-04-04-19-11-47.bpo-36523.sG1Tr4.rst

diff --git a/Lib/_pyio.py b/Lib/_pyio.py
index e868fdc7cbc..af2ce30c278 100644
--- a/Lib/_pyio.py
+++ b/Lib/_pyio.py
@@ -551,6 +551,11 @@ class IOBase(metaclass=abc.ABCMeta):
         return lines
 
     def writelines(self, lines):
+        """Write a list of lines to the stream.
+
+        Line separators are not added, so it is usual for each of the lines
+        provided to have a line separator at the end.
+        """
         self._checkClosed()
         for line in lines:
             self.write(line)
diff --git a/Misc/NEWS.d/next/Documentation/2019-04-04-19-11-47.bpo-36523.sG1Tr4.rst b/Misc/NEWS.d/next/Documentation/2019-04-04-19-11-47.bpo-36523.sG1Tr4.rst
new file mode 100644
index 00000000000..9355f607d76
--- /dev/null
+++ b/Misc/NEWS.d/next/Documentation/2019-04-04-19-11-47.bpo-36523.sG1Tr4.rst
@@ -0,0 +1 @@
+Add docstring for io.IOBase.writelines().
diff --git a/Modules/_io/clinic/iobase.c.h b/Modules/_io/clinic/iobase.c.h
index a5c8eea3ec3..ddaff7b5d13 100644
--- a/Modules/_io/clinic/iobase.c.h
+++ b/Modules/_io/clinic/iobase.c.h
@@ -242,7 +242,11 @@ exit:
 PyDoc_STRVAR(_io__IOBase_writelines__doc__,
 "writelines($self, lines, /)\n"
 "--\n"
-"\n");
+"\n"
+"Write a list of lines to stream.\n"
+"\n"
+"Line separators are not added, so it is usual for each of the\n"
+"lines provided to have a line separator at the end.");
 
 #define _IO__IOBASE_WRITELINES_METHODDEF    \
     {"writelines", (PyCFunction)_io__IOBase_writelines, METH_O, _io__IOBase_writelines__doc__},
@@ -311,4 +315,4 @@ _io__RawIOBase_readall(PyObject *self, PyObject *Py_UNUSED(ignored))
 {
     return _io__RawIOBase_readall_impl(self);
 }
-/*[clinic end generated code: output=60e43a7cbd9f314e input=a9049054013a1b77]*/
+/*[clinic end generated code: output=61b6ea7153ef9940 input=a9049054013a1b77]*/
diff --git a/Modules/_io/iobase.c b/Modules/_io/iobase.c
index 3a8f16ae0b6..6a0d9bec5af 100644
--- a/Modules/_io/iobase.c
+++ b/Modules/_io/iobase.c
@@ -751,11 +751,16 @@ _io__IOBase_readlines_impl(PyObject *self, Py_ssize_t hint)
 _io._IOBase.writelines
     lines: object
     /
+
+Write a list of lines to stream.
+
+Line separators are not added, so it is usual for each of the
+lines provided to have a line separator at the end.
 [clinic start generated code]*/
 
 static PyObject *
 _io__IOBase_writelines(PyObject *self, PyObject *lines)
-/*[clinic end generated code: output=976eb0a9b60a6628 input=432e729a8450b3cb]*/
+/*[clinic end generated code: output=976eb0a9b60a6628 input=cac3fc8864183359]*/
 {
     PyObject *iter, *res;