Index: Doc/lib/libstdtypes.tex
===================================================================
RCS file: /cvsroot/python/python/dist/src/Doc/lib/libstdtypes.tex,v
retrieving revision 1.180
diff -u -p -r1.180 libstdtypes.tex
--- Doc/lib/libstdtypes.tex	31 May 2005 11:03:59 -0000	1.180
+++ Doc/lib/libstdtypes.tex	5 Jun 2005 16:31:04 -0000
@@ -1628,12 +1628,14 @@ to a file, they will be converted to byt
 In addition, when the file is connected to a terminal, the attribute
 gives the encoding that the terminal is likely to use (that 
 information might be incorrect if the user has misconfigured the 
-terminal). The attribute is read-only and may not be present on
-all file-like objects. It may also be \code{None}, in which case
-the file uses the system default encoding for converting Unicode
-strings.
+terminal). The attribute may not be present on all file-like objects.
+It may also be \code{None}, in which case the file uses the system
+default encoding for converting Unicode strings.
 
 \versionadded{2.3}
+\versionchanged[The encoding attribute is now writable and is used
+for encoding Unicode strings given to \method{write()} and 
+\method{writelines()}]{2.5}
 \end{memberdesc}
 
 \begin{memberdesc}[file]{mode}
Index: Lib/test/test_file.py
===================================================================
RCS file: /cvsroot/python/python/dist/src/Lib/test/test_file.py,v
retrieving revision 1.17
diff -u -p -r1.17 test_file.py
--- Lib/test/test_file.py	20 May 2005 03:07:04 -0000	1.17
+++ Lib/test/test_file.py	5 Jun 2005 16:31:04 -0000
@@ -175,6 +175,62 @@ else:
 
 os.unlink(TESTFN)
 
+# verify write/writelines with unicode objects
+try:
+    unicode
+except NameError:
+    pass
+else:
+    testuni = 'test\xec\xa1\xb0\xec\x95\x84\xeb\x9d\xbc'.decode('utf-8')
+
+    # file.write(unicode)
+    f = file(TESTFN, 'w')
+    f.encoding = 'utf-8'
+    f.write(testuni)
+    f.close()
+
+    if file(TESTFN).read() != testuni.encode('utf-8'):
+        raise TestFailed, ('file.write() wrote wrongly encoded string for '
+                           'unicode')
+
+    # file.writelines([unicode, ..])
+    f = file(TESTFN, 'w')
+    f.encoding = 'utf-8'
+    f.writelines([testuni[:5], testuni[5], testuni[6]])
+    f.close()
+
+    if file(TESTFN).read() != testuni.encode('utf-8'):
+        raise TestFailed, ('file.writelines() wrote wrongly encoded string '
+                           'for unicode')
+
+    # test whether file.write(unencodable unicode) raises exceptions
+    f = file(TESTFN, 'w')
+    f.encoding = 'ascii'
+    try:
+        try:
+            f.write(testuni)
+        except UnicodeEncodeError:
+            pass
+        else:
+            raise TestFailed, ("file.write() doesn't pass UnicodeEncodeError "
+                               "correctly")
+    finally:
+        f.close()
+
+    # test whether file.writelines(unencodable unicode) raises exceptions
+    f = file(TESTFN, 'w')
+    f.encoding = 'ascii'
+    try:
+        try:
+            f.writelines(['1', '2', testuni, '3'])
+        except UnicodeEncodeError:
+            pass
+        else:
+            raise TestFailed, ("file.writelines() doesn't pass "
+                               "UnicodeEncodeError correctly")
+    finally:
+        f.close()
+
 def bug801631():
     # SF bug <http://www.python.org/sf/801631>
     # "file.truncate fault on windows"
Index: Objects/fileobject.c
===================================================================
RCS file: /cvsroot/python/python/dist/src/Objects/fileobject.c,v
retrieving revision 2.194
diff -u -p -r2.194 fileobject.c
--- Objects/fileobject.c	20 May 2005 03:07:05 -0000	2.194
+++ Objects/fileobject.c	5 Jun 2005 16:31:05 -0000
@@ -323,7 +323,7 @@ PyFile_SetBufSize(PyObject *f, int bufsi
 }
 
 /* Set the encoding used to output Unicode strings.
-   Returh 1 on success, 0 on failure. */
+   Return 1 on success, 0 on failure. */
 
 int
 PyFile_SetEncoding(PyObject *f, const char *enc)
@@ -1430,11 +1430,20 @@ file_readlines(PyFileObject *f, PyObject
 static PyObject *
 file_write(PyFileObject *f, PyObject *args)
 {
-	char *s;
+	char *s = NULL;
+	char *enc;
 	int n, n2;
+
 	if (f->f_fp == NULL)
 		return err_closed();
-	if (!PyArg_ParseTuple(args, f->f_binary ? "s#" : "t#", &s, &n))
+
+	assert(f->f_encoding == Py_None || PyString_Check(f->f_encoding));
+	if (f->f_encoding == Py_None)
+		enc = NULL;
+	else
+		enc = PyString_AS_STRING(f->f_encoding);
+
+	if (!PyArg_ParseTuple(args, "et#", enc, &s, &n))
 		return NULL;
 	f->f_softspace = 0;
 	Py_BEGIN_ALLOW_THREADS
@@ -1458,11 +1467,20 @@ file_writelines(PyFileObject *f, PyObjec
 	PyObject *it;	/* iter(seq) */
 	PyObject *result;
 	int i, j, index, len, nwritten, islist;
+	char *encoding;
 
 	assert(seq != NULL);
 	if (f->f_fp == NULL)
 		return err_closed();
 
+	/* Get current encoding name for encoding Unicode strings in
+	   the list. */
+	assert(f->f_encoding == Py_None || PyString_Check(f->f_encoding));
+	if (f->f_encoding == Py_None)
+		encoding = NULL;
+	else
+		encoding = PyString_AS_STRING(f->f_encoding);
+
 	result = NULL;
 	list = NULL;
 	islist = PyList_Check(seq);
@@ -1513,7 +1531,15 @@ file_writelines(PyFileObject *f, PyObjec
 		   could potentially execute Python code. */
 		for (i = 0; i < j; i++) {
 			PyObject *v = PyList_GET_ITEM(list, i);
-			if (!PyString_Check(v)) {
+			if (PyUnicode_Check(v)) {
+				line = PyUnicode_AsEncodedString(v, encoding,
+								 NULL);
+				if (line == NULL)
+					goto error;
+				Py_DECREF(v);
+				PyList_SET_ITEM(list, i, line);
+			}
+			else if (!PyString_Check(v)) {
 			    	const char *buffer;
 			    	int len;
 				if (((f->f_binary &&
@@ -1690,9 +1716,7 @@ static PyMemberDef file_memberlist[] = {
 	 "file mode ('r', 'U', 'w', 'a', possibly with 'b' or '+' added)"},
 	{"name",	T_OBJECT,	OFF(f_name),	RO,
 	 "file name"},
-	{"encoding",	T_OBJECT,	OFF(f_encoding),	RO,
-	 "file encoding"},
-	/* getattr(f, "closed") is implemented without this table */
+	/* "closed" and "encoding" is implemented in file_getsetlist */
 	{NULL}	/* Sentinel */
 };
 
@@ -1730,10 +1754,35 @@ get_newlines(PyFileObject *f, void *clos
 	}
 }
 
+static PyObject *
+get_encoding(PyFileObject *f, void *closure)
+{
+	Py_INCREF(f->f_encoding);
+	return f->f_encoding;
+}
+
+static int
+set_encoding(PyFileObject *f, PyObject *value)
+{
+	char *val;
+	if (value == Py_None) {
+		Py_DECREF(f->f_encoding);
+		Py_INCREF(Py_None);
+		f->f_encoding = Py_None;
+		return 0;
+	}
+	val = PyString_AsString(value);
+	if (val == NULL || PyFile_SetEncoding((PyObject*)f, val) == 0)
+		return -1;
+	return 0;
+}
+
 static PyGetSetDef file_getsetlist[] = {
 	{"closed", (getter)get_closed, NULL, "True if the file is closed"},
 	{"newlines", (getter)get_newlines, NULL,
 	 "end-of-line convention used in this file"},
+	{"encoding", (getter)get_encoding, (setter)set_encoding,
+	 "file encoding"},
 	{0},
 };