traverseda
/
cpython
1
0
Fork 0
Code Issues Pull Requests Releases Wiki Activity

Add bytes/bytearray.maketrans() to mirror str.maketrans(), and deprecate 

string.maketrans() which actually works on bytes.  (Also closes #5675.)
This commit is contained in:
Georg Brandl 2009-04-12 15:51:51 +00:00
parent 78532baeab
commit abc387747d
11 changed files with 134 additions and 32 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

27
Doc/library/stdtypes.rst
View File

@ -479,7 +479,7 @@ debugging, and in numerical work.
exponent.
.. method:: float.fromhex(s)
.. classmethod:: float.fromhex(s)
Class method to return the float represented by a hexadecimal
string *s*. The string *s* may have leading and trailing
@ -967,7 +967,7 @@ functions based on regular expressions.
'example.com'
.. method:: str.maketrans(x[, y[, z]])
.. staticmethod:: str.maketrans(x[, y[, z]])
This static method returns a translation table usable for :meth:`str.translate`.
@ -1514,8 +1514,8 @@ Wherever one of these methods needs to interpret the bytes as characters
The bytes and bytearray types have an additional class method:
.. method:: bytes.fromhex(string)
bytearray.fromhex(string)
.. classmethod:: bytes.fromhex(string)
bytearray.fromhex(string)
This :class:`bytes` class method returns a bytes or bytearray object,
decoding the given string object. The string must contain two hexadecimal
@ -1524,7 +1524,9 @@ The bytes and bytearray types have an additional class method:
>>> bytes.fromhex('f0 f1f2 ')
b'\xf0\xf1\xf2'
The translate method differs in semantics from the version available on strings:
The maketrans and translate methods differ in semantics from the versions
available on strings:
.. method:: bytes.translate(table[, delete])
@ -1533,8 +1535,7 @@ The translate method differs in semantics from the version available on strings:
mapped through the given translation table, which must be a bytes object of
length 256.
You can use the :func:`string.maketrans` helper function to create a
translation table.
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::
@ -1543,6 +1544,16 @@ The translate method differs in semantics from the version available on strings:
b'rd ths shrt txt'
.. staticmethod:: bytes.maketrans(from, to)
This static method returns a translation table usable for
:meth:`bytes.translate` that will map each character in *from* into the
character at the same position in *to*; *from* and *to* must be bytes objects
and have the same length.
.. versionadded:: 3.1
.. _types-set:
Set Types --- :class:`set`, :class:`frozenset`
@ -1847,7 +1858,7 @@ pairs within braces, for example: ``{'jack': 4098, 'sjoerd': 4127}`` or ``{4098:
Return a shallow copy of the dictionary.
.. method:: fromkeys(seq[, value])
.. classmethod:: fromkeys(seq[, value])
Create a new dictionary with keys from *seq* and values set to *value*.

9
Doc/library/string.rst
View File

@ -548,13 +548,9 @@ rule:
delimiter), and it should appear last in the regular expression.
String functions
Helper functions
----------------
The following functions are available to operate on string objects.
They are not available as string methods.
.. function:: capwords(s)
Split the argument into words using :func:`split`, capitalize each word using
@ -568,3 +564,6 @@ They are not available as string methods.
Return a translation table suitable for passing to :meth:`bytes.translate`,
that will map each character in *from* into the character at the same
position in *to*; *from* and *to* must have the same length.
.. deprecated:: 3.1
Use the :meth:`bytes.maketrans` static method instead.

4
Include/bytes_methods.h
View File

@ -20,6 +20,9 @@ extern void _Py_bytes_title(char *result, char *s, Py_ssize_t len);
extern void _Py_bytes_capitalize(char *result, char *s, Py_ssize_t len);
extern void _Py_bytes_swapcase(char *result, char *s, Py_ssize_t len);
/* This one gets the raw argument list. */
extern PyObject* _Py_bytes_maketrans(PyObject *args);
/* Shared __doc__ strings. */
extern const char _Py_isspace__doc__[];
extern const char _Py_isalpha__doc__[];
@ -33,6 +36,7 @@ extern const char _Py_upper__doc__[];
extern const char _Py_title__doc__[];
extern const char _Py_capitalize__doc__[];
extern const char _Py_swapcase__doc__[];
extern const char _Py_maketrans__doc__[];
#define FLAG_LOWER 0x01
#define FLAG_UPPER 0x02

3
Lib/string.py
View File

@ -49,6 +49,9 @@ def maketrans(frm: bytes, to: bytes) -> bytes:
mapped to the byte at the same position in to.
The strings frm and to must be of the same length.
"""
import warnings
warnings.warn("string.maketrans is deprecated, use bytes.maketrans instead",
DeprecationWarning)
if len(frm) != len(to):
raise ValueError("maketrans arguments must have same length")
if not (isinstance(frm, bytes) and isinstance(to, bytes)):

19
Lib/test/test_bigmem.py
View File

@ -418,18 +418,15 @@ class BaseStrTest:
@bigmemtest(minsize=_2G, memuse=2)
def test_translate(self, size):
_ = self.from_latin1
trans = {
ord(_('.')): _('-'),
ord(_('a')): _('!'),
ord(_('Z')): _('$'),
}
SUBSTR = _('aZz.z.Aaz.')
if not isinstance(SUBSTR, str):
# Workaround the inexistence of bytes.maketrans()
chars = bytearray(range(256))
for k, v in trans.items():
chars[k] = ord(v)
trans = chars
if isinstance(SUBSTR, str):
trans = {
ord(_('.')): _('-'),
ord(_('a')): _('!'),
ord(_('Z')): _('$'),
}
else:
trans = bytes.maketrans(b'.aZ', b'-!$')
sublen = len(SUBSTR)
repeats = size // sublen + 2
s = SUBSTR * repeats

7
Lib/test/test_bytes.py
View File

@ -450,6 +450,13 @@ class BaseBytesTest(unittest.TestCase):
self.assertEqual([ord(b[i:i+1]) for i in range(len(b))],
[0, 65, 127, 128, 255])
def test_maketrans(self):
transtable = b'\000\001\002\003\004\005\006\007\010\011\012\013\014\015\016\017\020\021\022\023\024\025\026\027\030\031\032\033\034\035\036\037 !"#$%&\'()*+,-./0123456789:;<=>?@ABCDEFGHIJKLMNOPQRSTUVWXYZ[\\]^_`xyzdefghijklmnopqrstuvwxyz{|}~\177\200\201\202\203\204\205\206\207\210\211\212\213\214\215\216\217\220\221\222\223\224\225\226\227\230\231\232\233\234\235\236\237\240\241\242\243\244\245\246\247\250\251\252\253\254\255\256\257\260\261\262\263\264\265\266\267\270\271\272\273\274\275\276\277\300\301\302\303\304\305\306\307\310\311\312\313\314\315\316\317\320\321\322\323\324\325\326\327\330\331\332\333\334\335\336\337\340\341\342\343\344\345\346\347\350\351\352\353\354\355\356\357\360\361\362\363\364\365\366\367\370\371\372\373\374\375\376\377'
self.assertEqual(self.type2test.maketrans(b'abc', b'xyz'), transtable)
self.assertRaises(ValueError, self.type2test.maketrans, b'abc', b'xyzq')
self.assertRaises(TypeError, self.type2test.maketrans, 'abc', 'def')
class BytesTest(BaseBytesTest):
type2test = bytes

8
Lib/test/test_string.py
View File

@ -101,14 +101,6 @@ class ModuleTest(unittest.TestCase):
self.assertRaises(ValueError, fmt.format, "{0}", 10, 20, i=100)
self.assertRaises(ValueError, fmt.format, "{i}", 10, 20, i=100)
def test_maketrans(self):
transtable = b'\000\001\002\003\004\005\006\007\010\011\012\013\014\015\016\017\020\021\022\023\024\025\026\027\030\031\032\033\034\035\036\037 !"#$%&\'()*+,-./0123456789:;<=>?@ABCDEFGHIJKLMNOPQRSTUVWXYZ[\\]^_`xyzdefghijklmnopqrstuvwxyz{|}~\177\200\201\202\203\204\205\206\207\210\211\212\213\214\215\216\217\220\221\222\223\224\225\226\227\230\231\232\233\234\235\236\237\240\241\242\243\244\245\246\247\250\251\252\253\254\255\256\257\260\261\262\263\264\265\266\267\270\271\272\273\274\275\276\277\300\301\302\303\304\305\306\307\310\311\312\313\314\315\316\317\320\321\322\323\324\325\326\327\330\331\332\333\334\335\336\337\340\341\342\343\344\345\346\347\350\351\352\353\354\355\356\357\360\361\362\363\364\365\366\367\370\371\372\373\374\375\376\377'
self.assertEqual(string.maketrans(b'abc', b'xyz'), transtable)
self.assertRaises(ValueError, string.maketrans, b'abc', b'xyzq')
self.assertRaises(TypeError, string.maketrans, 'abc', 'def')
def test_main():
support.run_unittest(ModuleTest)

5
Misc/NEWS
View File

@ -12,6 +12,11 @@ What's New in Python 3.1 beta 1?
Core and Builtins
-----------------
- The string.maketrans() function is deprecated; there is a new static method
maketrans() on the bytes and bytearray classes. This removes confusion about
the types string.maketrans() is supposed to work with, and mirrors the
methods available on the str class.
- Issue #2170: refactored xml.dom.minidom.normalize, increasing both
its clarity and its speed.

9
Objects/bytearrayobject.c
View File

@ -1451,6 +1451,13 @@ done:
}
static PyObject *
bytes_maketrans(PyObject *null, PyObject *args)
{
return _Py_bytes_maketrans(args);
}
#define FORWARD 1
#define REVERSE -1
@ -3131,6 +3138,8 @@ bytes_methods[] = {
{"ljust", (PyCFunction)stringlib_ljust, METH_VARARGS, ljust__doc__},
{"lower", (PyCFunction)stringlib_lower, METH_NOARGS, _Py_lower__doc__},
{"lstrip", (PyCFunction)bytes_lstrip, METH_VARARGS, lstrip__doc__},
{"maketrans", (PyCFunction)bytes_maketrans, METH_VARARGS|METH_STATIC,
_Py_maketrans__doc__},
{"partition", (PyCFunction)bytes_partition, METH_O, partition__doc__},
{"pop", (PyCFunction)bytes_pop, METH_VARARGS, pop__doc__},
{"remove", (PyCFunction)bytes_remove, METH_O, remove__doc__},

67
Objects/bytes_methods.c
View File

@ -608,3 +608,70 @@ _Py_bytes_swapcase(char *result, char *s, Py_ssize_t len)
}
}
PyDoc_STRVAR_shared(_Py_maketrans__doc__,
"B.maketrans(frm, to) -> translation table\n\
\n\
Return a translation table (a bytes object of length 256)\n\
suitable for use in bytes.translate where each byte in frm is\n\
mapped to the byte at the same position in to.\n\
The strings frm and to must be of the same length.");
static Py_ssize_t
_getbuffer(PyObject *obj, Py_buffer *view)
{
PyBufferProcs *buffer = Py_TYPE(obj)->tp_as_buffer;
if (buffer == NULL || buffer->bf_getbuffer == NULL)
{
PyErr_Format(PyExc_TypeError,
"Type %.100s doesn't support the buffer API",
Py_TYPE(obj)->tp_name);
return -1;
}
if (buffer->bf_getbuffer(obj, view, PyBUF_SIMPLE) < 0)
return -1;
return view->len;
}
PyObject *
_Py_bytes_maketrans(PyObject *args)
{
PyObject *frm, *to, *res = NULL;
Py_buffer bfrm, bto;
int i;
char *p;
bfrm.len = -1;
bto.len = -1;
if (!PyArg_ParseTuple(args, "OO:maketrans", &frm, &to))
return NULL;
if (_getbuffer(frm, &bfrm) < 0)
return NULL;
if (_getbuffer(to, &bto) < 0)
goto done;
if (bfrm.len != bto.len) {
PyErr_Format(PyExc_ValueError,
"maketrans arguments must have same length");
goto done;
}
res = PyBytes_FromStringAndSize(NULL, 256);
if (!res) {
goto done;
}
p = PyBytes_AS_STRING(res);
for (i = 0; i < 256; i++)
p[i] = i;
for (i = 0; i < bfrm.len; i++) {
p[(int)((char *)bfrm.buf)[i]] = ((char *)bto.buf)[i];
}
done:
if (bfrm.len != -1)
PyBuffer_Release(&bfrm);
if (bto.len != -1)
PyBuffer_Release(&bto);
return res;
}

8
Objects/bytesobject.c
View File

@ -1950,6 +1950,12 @@ string_translate(PyBytesObject *self, PyObject *args)
}
static PyObject *
string_maketrans(PyObject *null, PyObject *args)
{
return _Py_bytes_maketrans(args);
}
#define FORWARD 1
#define REVERSE -1
@ -2851,6 +2857,8 @@ string_methods[] = {
{"ljust", (PyCFunction)stringlib_ljust, METH_VARARGS, ljust__doc__},
{"lower", (PyCFunction)stringlib_lower, METH_NOARGS, _Py_lower__doc__},
{"lstrip", (PyCFunction)string_lstrip, METH_VARARGS, lstrip__doc__},
{"maketrans", (PyCFunction)string_maketrans, METH_VARARGS|METH_STATIC,
_Py_maketrans__doc__},
{"partition", (PyCFunction)string_partition, METH_O, partition__doc__},
{"replace", (PyCFunction)string_replace, METH_VARARGS, replace__doc__},
{"rfind", (PyCFunction)string_rfind, METH_VARARGS, rfind__doc__},