bpo-38378: Rename parameters "out" and "in" of os.sendfile(). (pythonGH-16742)

They conflicted with keyword "in".

Also rename positional-only parameters of private os._fcopyfile()
for consistency.

Author: serhiy-storchaka

Doc/library/os.rst

@@ -1251,27 +1251,27 @@ or `the MSDN <https://msdn.microsoft.com/en-us/library/z0kc8e3z.aspx>`_ on Windo
       :exc:`InterruptedError` exception (see :pep:`475` for the rationale).
 
 
-.. function:: sendfile(out, in, offset, count)
-              sendfile(out, in, offset, count, [headers], [trailers], flags=0)
+.. function:: sendfile(out_fd, in_fd, offset, count)
+              sendfile(out_fd, in_fd, offset, count, [headers], [trailers], flags=0)
 
-   Copy *count* bytes from file descriptor *in* to file descriptor *out*
+   Copy *count* bytes from file descriptor *in_fd* to file descriptor *out_fd*
    starting at *offset*.
-   Return the number of bytes sent. When EOF is reached return 0.
+   Return the number of bytes sent. When EOF is reached return ``0``.
 
    The first function notation is supported by all platforms that define
    :func:`sendfile`.
 
    On Linux, if *offset* is given as ``None``, the bytes are read from the
-   current position of *in* and the position of *in* is updated.
+   current position of *in_fd* and the position of *in_fd* is updated.
 
    The second case may be used on Mac OS X and FreeBSD where *headers* and
    *trailers* are arbitrary sequences of buffers that are written before and
-   after the data from *in* is written. It returns the same as the first case.
+   after the data from *in_fd* is written. It returns the same as the first case.
 
-   On Mac OS X and FreeBSD, a value of 0 for *count* specifies to send until
-   the end of *in* is reached.
+   On Mac OS X and FreeBSD, a value of ``0`` for *count* specifies to send until
+   the end of *in_fd* is reached.
 
-   All platforms support sockets as *out* file descriptor, and some platforms
+   All platforms support sockets as *out_fd* file descriptor, and some platforms
    allow other types (e.g. regular file, pipe) as well.
 
    Cross-platform applications should not use *headers*, *trailers* and *flags*
@@ -1286,6 +1286,9 @@ or `the MSDN <https://msdn.microsoft.com/en-us/library/z0kc8e3z.aspx>`_ on Windo
 
    .. versionadded:: 3.3
 
+   .. versionchanged:: 3.9
+      Parameters *out* and *in* was renamed to *out_fd* and *in_fd*.
+
 
 .. function:: set_blocking(fd, blocking)
 

Lib/test/test_os.py

@@ -3110,11 +3110,12 @@ def test_invalid_offset(self):
 
     def test_keywords(self):
         # Keyword arguments should be supported
-        os.sendfile(out=self.sockno, offset=0, count=4096,
-            **{'in': self.fileno})
+        os.sendfile(out_fd=self.sockno, in_fd=self.fileno,
+                    offset=0, count=4096)
         if self.SUPPORT_HEADERS_TRAILERS:
-            os.sendfile(self.sockno, self.fileno, offset=0, count=4096,
-                headers=(), trailers=(), flags=0)
+            os.sendfile(out_fd=self.sockno, in_fd=self.fileno,
+                        offset=0, count=4096,
+                        headers=(), trailers=(), flags=0)
 
     # --- headers / trailers tests
 

Misc/NEWS.d/next/Library/2019-10-13-11-00-03.bpo-38378.yYNpSm.rst

@@ -0,0 +1,2 @@
+Parameters *out* and *in* of :func:`os.sendfile` was renamed to *out_fd* and
+*in_fd*.

Modules/clinic/posixmodule.c.h

@@ -8993,10 +8993,10 @@ os_write_impl(PyObject *module, int fd, Py_buffer *data)
 
 #ifdef HAVE_SENDFILE
 PyDoc_STRVAR(posix_sendfile__doc__,
-"sendfile(out, in, offset, count) -> byteswritten\n\
-sendfile(out, in, offset, count[, headers][, trailers], flags=0)\n\
+"sendfile(out_fd, in_fd, offset, count) -> byteswritten\n\
+sendfile(out_fd, in_fd, offset, count[, headers][, trailers], flags=0)\n\
             -> byteswritten\n\
-Copy count bytes from file descriptor in to file descriptor out.");
+Copy count bytes from file descriptor in_fd to file descriptor out_fd.");
 
 /* AC 3.5: don't bother converting, has optional group*/
 static PyObject *
@@ -9016,8 +9016,7 @@ posix_sendfile(PyObject *self, PyObject *args, PyObject *kwdict)
     off_t sbytes;
     struct sf_hdtr sf;
     int flags = 0;
-    /* Beware that "in" clashes with Python's own "in" operator keyword */
-    static char *keywords[] = {"out", "in",
+    static char *keywords[] = {"out_fd", "in_fd",
                                 "offset", "count",
                                 "headers", "trailers", "flags", NULL};
 
@@ -9133,7 +9132,7 @@ posix_sendfile(PyObject *self, PyObject *args, PyObject *kwdict)
 #else
     Py_ssize_t count;
     PyObject *offobj;
-    static char *keywords[] = {"out", "in",
+    static char *keywords[] = {"out_fd", "in_fd",
                                 "offset", "count", NULL};
     if (!PyArg_ParseTupleAndKeywords(args, kwdict, "iiOn:sendfile",
             keywords, &out, &in, &offobj, &count))
@@ -9170,22 +9169,22 @@ posix_sendfile(PyObject *self, PyObject *args, PyObject *kwdict)
 /*[clinic input]
 os._fcopyfile
 
-    infd: int
-    outfd: int
+    in_fd: int
+    out_fd: int
     flags: int
     /
 
 Efficiently copy content or metadata of 2 regular file descriptors (macOS).
 [clinic start generated code]*/
 
 static PyObject *
-os__fcopyfile_impl(PyObject *module, int infd, int outfd, int flags)
-/*[clinic end generated code: output=8e8885c721ec38e3 input=69e0770e600cb44f]*/
+os__fcopyfile_impl(PyObject *module, int in_fd, int out_fd, int flags)
+/*[clinic end generated code: output=c9d1a35a992e401b input=1e34638a86948795]*/
 {
     int ret;
 
     Py_BEGIN_ALLOW_THREADS
-    ret = fcopyfile(infd, outfd, NULL, flags);
+    ret = fcopyfile(in_fd, out_fd, NULL, flags);
     Py_END_ALLOW_THREADS
     if (ret < 0)
         return posix_error();