# HG changeset patch
# Parent  2f0716009132ad56aa1718aeaf072afd9c209076
Issue #27506: Make bytes.translate() table optional, support delete keyword

diff -r 2f0716009132 Doc/library/stdtypes.rst
--- a/Doc/library/stdtypes.rst	Tue Jul 12 18:24:25 2016 -0400
+++ b/Doc/library/stdtypes.rst	Sat Jul 23 13:04:27 2016 +0000
@@ -2631,8 +2631,8 @@
    The prefix(es) to search for may be any :term:`bytes-like object`.
 
 
-.. method:: bytes.translate(table[, delete])
-            bytearray.translate(table[, delete])
+.. method:: bytes.translate([table, ]delete=b'')
+            bytearray.translate([table, ]delete=b'')
 
    Return a copy of the bytes or bytearray object where all bytes occurring in
    the optional argument *delete* are removed, and the remaining bytes have
@@ -2642,12 +2642,16 @@
    You can use the :func:`bytes.maketrans` method to create a translation
    table.
 
-   Set the *table* argument to ``None`` for translations that only delete
-   characters::
-
-      >>> b'read this short text'.translate(None, b'aeiou')
+   The *table* argument may be omitted (or set to ``None``) for
+   translations that only delete characters::
+
+      >>> b'read this short text'.translate(delete=b'aeiou')
       b'rd ths shrt txt'
 
+   .. versionadded:: 3.6
+      *table* is now optional, and *delete* is now supported as a
+      keyword argument.
+
 
 The following methods on bytes and bytearray objects have default behaviours
 that assume the use of ASCII compatible binary formats, but can still be used
diff -r 2f0716009132 Lib/test/test_bytes.py
--- a/Lib/test/test_bytes.py	Tue Jul 12 18:24:25 2016 -0400
+++ b/Lib/test/test_bytes.py	Sat Jul 23 13:04:27 2016 +0000
@@ -1424,6 +1424,7 @@
         ba = bytearray(b)
         rosetta = bytearray(range(0, 256))
         rosetta[ord('o')] = ord('e')
+
         c = b.translate(rosetta, b'l')
         self.assertEqual(b, b'hello')
         self.assertEqual(c, b'hee')
@@ -1437,6 +1438,35 @@
         self.assertRaises(TypeError, b.translate, None, None)
         self.assertRaises(TypeError, ba.translate, None, None)
 
+        self.assertRaises(ValueError, b.translate, bytes(range(255)))
+        self.assertRaises(ValueError, ba.translate, bytes(range(255)))
+        c = b.translate(rosetta)
+        self.assertEqual(c, b'helle')
+        c = ba.translate(rosetta)
+        self.assertEqual(c, b'helle')
+        c = b.translate(rosetta, b'')
+        self.assertEqual(c, b'helle')
+        c = ba.translate(rosetta, b'')
+        self.assertEqual(c, b'helle')
+        c = b.translate()
+        self.assertEqual(c, b'hello')
+        c = ba.translate()
+        self.assertEqual(c, b'hello')
+
+        # test delete as a keyword argument
+        c = b.translate(rosetta, delete=b'l')
+        self.assertEqual(c, b'hee')
+        c = ba.translate(rosetta, delete=b'l')
+        self.assertEqual(c, b'hee')
+        c = b.translate(None, delete=b'l')
+        self.assertEqual(c, b'heo')
+        c = ba.translate(None, delete=b'l')
+        self.assertEqual(c, b'heo')
+        c = b.translate(delete=b'l')
+        self.assertEqual(c, b'heo')
+        c = ba.translate(delete=b'l')
+        self.assertEqual(c, b'heo')
+
     def test_split_bytearray(self):
         self.assertEqual(b'a b'.split(memoryview(b' ')), [b'a', b'b'])
 
diff -r 2f0716009132 Objects/bytearrayobject.c
--- a/Objects/bytearrayobject.c	Tue Jul 12 18:24:25 2016 -0400
+++ b/Objects/bytearrayobject.c	Sat Jul 23 13:04:27 2016 +0000
@@ -1175,23 +1175,21 @@
 /*[clinic input]
 bytearray.translate
 
-    table: object
+    table: object = None
         Translation table, which must be a bytes object of length 256.
-    [
-    deletechars: object
-    ]
     /
+    delete as deletechars: object(c_default="NULL") = b''
 
 Return a copy with each character mapped by the given translation table.
 
-All characters occurring in the optional argument deletechars are removed.
+All characters occurring in the optional argument delete are removed.
 The remaining characters are mapped through the given translation table.
 [clinic start generated code]*/
 
 static PyObject *
 bytearray_translate_impl(PyByteArrayObject *self, PyObject *table,
-                         int group_right_1, PyObject *deletechars)
-/*[clinic end generated code: output=2bebc86a9a1ff083 input=846a01671bccc1c5]*/
+                         PyObject *deletechars)
+/*[clinic end generated code: output=b6a8f01c2a74e446 input=3579ac52f2e92b5e]*/
 {
     char *input, *output;
     const char *table_chars;
@@ -1260,8 +1258,7 @@
     for (i = inlen; --i >= 0; ) {
         c = Py_CHARMASK(*input++);
         if (trans_table[c] != -1)
-            if (Py_CHARMASK(*output++ = (char)trans_table[c]) == c)
-                    continue;
+            *output++ = (char)trans_table[c];
     }
     /* Fix the size of the resulting string */
     if (inlen > 0)
diff -r 2f0716009132 Objects/bytesobject.c
--- a/Objects/bytesobject.c	Tue Jul 12 18:24:25 2016 -0400
+++ b/Objects/bytesobject.c	Sat Jul 23 13:04:27 2016 +0000
@@ -2043,23 +2043,21 @@
 /*[clinic input]
 bytes.translate
 
-    table: object
+    table: object = None
         Translation table, which must be a bytes object of length 256.
-    [
-    deletechars: object
-    ]
     /
+    delete as deletechars: object(c_default="NULL") = b''
 
 Return a copy with each character mapped by the given translation table.
 
-All characters occurring in the optional argument deletechars are removed.
+All characters occurring in the optional argument delete are removed.
 The remaining characters are mapped through the given translation table.
 [clinic start generated code]*/
 
 static PyObject *
-bytes_translate_impl(PyBytesObject *self, PyObject *table, int group_right_1,
+bytes_translate_impl(PyBytesObject *self, PyObject *table,
                      PyObject *deletechars)
-/*[clinic end generated code: output=233df850eb50bf8d input=ca20edf39d780d49]*/
+/*[clinic end generated code: output=43be3437f1956211 input=63cf44ea510e147d]*/
 {
     char *input, *output;
     Py_buffer table_view = {NULL, NULL};
@@ -2123,12 +2121,14 @@
     output_start = output = PyBytes_AS_STRING(result);
     input = PyBytes_AS_STRING(input_obj);
 
-    if (dellen == 0 && table_chars != NULL) {
+    if (dellen == 0) {
         /* If no deletions are required, use faster code */
-        for (i = inlen; --i >= 0; ) {
-            c = Py_CHARMASK(*input++);
-            if (Py_CHARMASK((*output++ = table_chars[c])) != c)
-                changed = 1;
+        if (table_chars != NULL) {
+            for (i = inlen; --i >= 0; ) {
+                c = Py_CHARMASK(*input++);
+                if (Py_CHARMASK((*output++ = table_chars[c])) != c)
+                    changed = 1;
+            }
         }
         if (!changed && PyBytes_CheckExact(input_obj)) {
             Py_INCREF(input_obj);
diff -r 2f0716009132 Objects/clinic/bytearrayobject.c.h
--- a/Objects/clinic/bytearrayobject.c.h	Tue Jul 12 18:24:25 2016 -0400
+++ b/Objects/clinic/bytearrayobject.c.h	Sat Jul 23 13:04:27 2016 +0000
@@ -39,47 +39,37 @@
 }
 
 PyDoc_STRVAR(bytearray_translate__doc__,
-"translate(table, [deletechars])\n"
+"translate($self, table=None, /, delete=b\'\')\n"
+"--\n"
+"\n"
 "Return a copy with each character mapped by the given translation table.\n"
 "\n"
 "  table\n"
 "    Translation table, which must be a bytes object of length 256.\n"
 "\n"
-"All characters occurring in the optional argument deletechars are removed.\n"
+"All characters occurring in the optional argument delete are removed.\n"
 "The remaining characters are mapped through the given translation table.");
 
 #define BYTEARRAY_TRANSLATE_METHODDEF    \
-    {"translate", (PyCFunction)bytearray_translate, METH_VARARGS, bytearray_translate__doc__},
+    {"translate", (PyCFunction)bytearray_translate, METH_VARARGS|METH_KEYWORDS, bytearray_translate__doc__},
 
 static PyObject *
 bytearray_translate_impl(PyByteArrayObject *self, PyObject *table,
-                         int group_right_1, PyObject *deletechars);
+                         PyObject *deletechars);
 
 static PyObject *
-bytearray_translate(PyByteArrayObject *self, PyObject *args)
+bytearray_translate(PyByteArrayObject *self, PyObject *args, PyObject *kwargs)
 {
     PyObject *return_value = NULL;
-    PyObject *table;
-    int group_right_1 = 0;
+    static char *_keywords[] = {"", "delete", NULL};
+    PyObject *table = Py_None;
     PyObject *deletechars = NULL;
 
-    switch (PyTuple_GET_SIZE(args)) {
-        case 1:
-            if (!PyArg_ParseTuple(args, "O:translate", &table)) {
-                goto exit;
-            }
-            break;
-        case 2:
-            if (!PyArg_ParseTuple(args, "OO:translate", &table, &deletechars)) {
-                goto exit;
-            }
-            group_right_1 = 1;
-            break;
-        default:
-            PyErr_SetString(PyExc_TypeError, "bytearray.translate requires 1 to 2 arguments");
-            goto exit;
+    if (!PyArg_ParseTupleAndKeywords(args, kwargs, "|OO:translate", _keywords,
+        &table, &deletechars)) {
+        goto exit;
     }
-    return_value = bytearray_translate_impl(self, table, group_right_1, deletechars);
+    return_value = bytearray_translate_impl(self, table, deletechars);
 
 exit:
     return return_value;
@@ -716,4 +706,4 @@
 {
     return bytearray_sizeof_impl(self);
 }
-/*[clinic end generated code: output=a32f183ebef159cc input=a9049054013a1b77]*/
+/*[clinic end generated code: output=440ca89f3c48384e input=a9049054013a1b77]*/
diff -r 2f0716009132 Objects/clinic/bytesobject.c.h
--- a/Objects/clinic/bytesobject.c.h	Tue Jul 12 18:24:25 2016 -0400
+++ b/Objects/clinic/bytesobject.c.h	Sat Jul 23 13:04:27 2016 +0000
@@ -267,47 +267,37 @@
 }
 
 PyDoc_STRVAR(bytes_translate__doc__,
-"translate(table, [deletechars])\n"
+"translate($self, table=None, /, delete=b\'\')\n"
+"--\n"
+"\n"
 "Return a copy with each character mapped by the given translation table.\n"
 "\n"
 "  table\n"
 "    Translation table, which must be a bytes object of length 256.\n"
 "\n"
-"All characters occurring in the optional argument deletechars are removed.\n"
+"All characters occurring in the optional argument delete are removed.\n"
 "The remaining characters are mapped through the given translation table.");
 
 #define BYTES_TRANSLATE_METHODDEF    \
-    {"translate", (PyCFunction)bytes_translate, METH_VARARGS, bytes_translate__doc__},
+    {"translate", (PyCFunction)bytes_translate, METH_VARARGS|METH_KEYWORDS, bytes_translate__doc__},
 
 static PyObject *
-bytes_translate_impl(PyBytesObject *self, PyObject *table, int group_right_1,
+bytes_translate_impl(PyBytesObject *self, PyObject *table,
                      PyObject *deletechars);
 
 static PyObject *
-bytes_translate(PyBytesObject *self, PyObject *args)
+bytes_translate(PyBytesObject *self, PyObject *args, PyObject *kwargs)
 {
     PyObject *return_value = NULL;
-    PyObject *table;
-    int group_right_1 = 0;
+    static char *_keywords[] = {"", "delete", NULL};
+    PyObject *table = Py_None;
     PyObject *deletechars = NULL;
 
-    switch (PyTuple_GET_SIZE(args)) {
-        case 1:
-            if (!PyArg_ParseTuple(args, "O:translate", &table)) {
-                goto exit;
-            }
-            break;
-        case 2:
-            if (!PyArg_ParseTuple(args, "OO:translate", &table, &deletechars)) {
-                goto exit;
-            }
-            group_right_1 = 1;
-            break;
-        default:
-            PyErr_SetString(PyExc_TypeError, "bytes.translate requires 1 to 2 arguments");
-            goto exit;
+    if (!PyArg_ParseTupleAndKeywords(args, kwargs, "|OO:translate", _keywords,
+        &table, &deletechars)) {
+        goto exit;
     }
-    return_value = bytes_translate_impl(self, table, group_right_1, deletechars);
+    return_value = bytes_translate_impl(self, table, deletechars);
 
 exit:
     return return_value;
@@ -504,4 +494,4 @@
 exit:
     return return_value;
 }
-/*[clinic end generated code: output=6fe884a74e7d49cf input=a9049054013a1b77]*/
+/*[clinic end generated code: output=596a9cb71b613c7e input=a9049054013a1b77]*/