[3.8] bpo-38580: Document that select() accepts iterables, not just sequences (GH-16832)

(cherry picked from commit 372ee27)

Co-authored-by: Jakub Stasiak <jakub@stasiak.at>

Author: taleinat

Doc/library/select.rst

@@ -117,7 +117,7 @@ The module defines the following:
 .. function:: select(rlist, wlist, xlist[, timeout])
 
    This is a straightforward interface to the Unix :c:func:`select` system call.
-   The first three arguments are sequences of 'waitable objects': either
+   The first three arguments are iterables of 'waitable objects': either
    integers representing file descriptors or objects with a parameterless method
    named :meth:`~io.IOBase.fileno` returning such an integer:
 
@@ -126,7 +126,7 @@ The module defines the following:
    * *xlist*: wait for an "exceptional condition" (see the manual page for what
      your system considers such a condition)
 
-   Empty sequences are allowed, but acceptance of three empty sequences is
+   Empty iterables are allowed, but acceptance of three empty iterables is
    platform-dependent. (It is known to work on Unix but not on Windows.)  The
    optional *timeout* argument specifies a time-out as a floating point number
    in seconds.  When the *timeout* argument is omitted the function blocks until
@@ -141,7 +141,7 @@ The module defines the following:
       single: socket() (in module socket)
       single: popen() (in module os)
 
-   Among the acceptable object types in the sequences are Python :term:`file
+   Among the acceptable object types in the iterables are Python :term:`file
    objects <file object>` (e.g. ``sys.stdin``, or objects returned by
    :func:`open` or :func:`os.popen`), socket objects returned by
    :func:`socket.socket`.  You may also define a :dfn:`wrapper` class yourself,

Modules/clinic/selectmodule.c.h

@@ -218,7 +218,7 @@ select.select
 
 Wait until one or more file descriptors are ready for some kind of I/O.
 
-The first three arguments are sequences of file descriptors to be waited for:
+The first three arguments are iterables of file descriptors to be waited for:
 rlist -- wait until ready for reading
 wlist -- wait until ready for writing
 xlist -- wait for an "exceptional condition"
@@ -243,7 +243,7 @@ descriptors can be used.
 static PyObject *
 select_select_impl(PyObject *module, PyObject *rlist, PyObject *wlist,
                    PyObject *xlist, PyObject *timeout_obj)
-/*[clinic end generated code: output=2b3cfa824f7ae4cf input=177e72184352df25]*/
+/*[clinic end generated code: output=2b3cfa824f7ae4cf input=e467f5d68033de00]*/
 {
 #ifdef SELECT_USES_HEAP
     pylist *rfd2obj, *wfd2obj, *efd2obj;
@@ -299,7 +299,7 @@ select_select_impl(PyObject *module, PyObject *rlist, PyObject *wlist,
     }
 #endif /* SELECT_USES_HEAP */
 
-    /* Convert sequences to fd_sets, and get maximum fd number
+    /* Convert iterables to fd_sets, and get maximum fd number
      * propagates the Python exception set in seq2set()
      */
     rfd2obj[0].sentinel = -1;