Mention the *limit* argument of TextIO.readline().
diff --git a/Doc/library/io.rst b/Doc/library/io.rst
index 1d1f490..4319931 100644
--- a/Doc/library/io.rst
+++ b/Doc/library/io.rst
@@ -696,11 +696,13 @@
Read and return at most *n* characters from the stream as a single
:class:`unicode`. If *n* is negative or ``None``, reads until EOF.
- .. method:: readline()
+ .. method:: readline(limit=-1)
Read until newline or EOF and return a single ``unicode``. If the
stream is already at EOF, an empty string is returned.
+ If *limit* is specified, at most *limit* characters will be read.
+
.. method:: seek(offset, whence=SEEK_SET)
Change the stream position to the given *offset*. Behaviour depends