gh-117431: Adapt str.{start,end}swith to use the METH_FASTCALL calling convention

Lib/test/string_tests.py

@@ -1513,9 +1513,9 @@ def test_find_etc_raise_correct_error_messages(self):
  x, None, None, None)
  self.assertRaisesRegex(TypeError, r'^count\(', s.count,
  x, None, None, None)
- self.assertRaisesRegex(TypeError, r'^startswith\(', s.startswith,
+ self.assertRaisesRegex(TypeError, r'^startswith\b', s.startswith,
  x, None, None, None)
- self.assertRaisesRegex(TypeError, r'^endswith\(', s.endswith,
+ self.assertRaisesRegex(TypeError, r'^endswith\b', s.endswith,
  x, None, None, None)
 
  # issue #15534

Misc/NEWS.d/next/Core and Builtins/2024-04-02-17-37-35.gh-issue-117431.vDKAOn.rst

@@ -0,0 +1,2 @@
+Improve the performance of :meth:`str.startswith` and :meth:`str.endswith`
+by adapting them to the :c:macro:`METH_FASTCALL` calling convention.

Objects/unicodeobject.c

@@ -13021,40 +13021,41 @@ unicode_zfill_impl(PyObject *self, Py_ssize_t width)
  return u;
 }
 
-PyDoc_STRVAR(startswith__doc__,
- "S.startswith(prefix[, start[, end]]) -> bool\n\
-\n\
-Return True if S starts with the specified prefix, False otherwise.\n\
-With optional start, test S beginning at that position.\n\
-With optional end, stop comparing S at that position.\n\
-prefix can also be a tuple of strings to try.");
+/*[clinic input]
+@text_signature "($self, prefix[, start[, end]], /)"
+str.startswith as unicode_startswith
+
+ prefix as subobj: object
+ A string or a tuple of strings to try.
+ start: slice_index(accept={int, NoneType}, c_default='0') = None
+ Optional start position. Default: start of the string.
+ end: slice_index(accept={int, NoneType}, c_default='PY_SSIZE_T_MAX') = None
+ Optional stop position. Default: end of the string.
+ /
+
+Return True if the string starts with the specified prefix, False otherwise.
+[clinic start generated code]*/
 
 static PyObject *
-unicode_startswith(PyObject *self,
- PyObject *args)
+unicode_startswith_impl(PyObject *self, PyObject *subobj, Py_ssize_t start,
+ Py_ssize_t end)
+/*[clinic end generated code: output=4bd7cfd0803051d4 input=5f918b5f5f89d856]*/
 {
- PyObject *subobj;
- PyObject *substring;
- Py_ssize_t start = 0;
- Py_ssize_t end = PY_SSIZE_T_MAX;
- int result;
-
- if (!asciilib_parse_args_finds("startswith", args, &subobj, &start, &end))
- return NULL;
  if (PyTuple_Check(subobj)) {
  Py_ssize_t i;
  for (i = 0; i < PyTuple_GET_SIZE(subobj); i++) {
- substring = PyTuple_GET_ITEM(subobj, i);
+PyObject *substring = PyTuple_GET_ITEM(subobj, i);
  if (!PyUnicode_Check(substring)) {
  PyErr_Format(PyExc_TypeError,
  "tuple for startswith must only contain str, "
  "not %.100s",
  Py_TYPE(substring)->tp_name);
  return NULL;
  }
- result = tailmatch(self, substring, start, end, -1);
- if (result == -1)
+int result = tailmatch(self, substring, start, end, -1);
+ if (result < 0) {
  return NULL;
+ }
  if (result) {
  Py_RETURN_TRUE;
  }
@@ -13068,47 +13069,41 @@ unicode_startswith(PyObject *self,
  "a tuple of str, not %.100s", Py_TYPE(subobj)->tp_name);
  return NULL;
  }
- result = tailmatch(self, subobj, start, end, -1);
- if (result == -1)
+int result = tailmatch(self, subobj, start, end, -1);
+ if (result < 0) {
  return NULL;
+ }
  return PyBool_FromLong(result);
 }
 
 
-PyDoc_STRVAR(endswith__doc__,
- "S.endswith(suffix[, start[, end]]) -> bool\n\
-\n\
-Return True if S ends with the specified suffix, False otherwise.\n\
-With optional start, test S beginning at that position.\n\
-With optional end, stop comparing S at that position.\n\
-suffix can also be a tuple of strings to try.");
+/*[clinic input]
+@text_signature "($self, prefix[, start[, end]], /)"
+str.endswith as unicode_endswith = str.startswith
+
+Return True if the string ends with the specified prefix, False otherwise.
+[clinic start generated code]*/
 
 static PyObject *
-unicode_endswith(PyObject *self,
- PyObject *args)
+unicode_endswith_impl(PyObject *self, PyObject *subobj, Py_ssize_t start,
+ Py_ssize_t end)
+/*[clinic end generated code: output=cce6f8ceb0102ca9 input=82cd5ce9e7623646]*/
 {
- PyObject *subobj;
- PyObject *substring;
- Py_ssize_t start = 0;
- Py_ssize_t end = PY_SSIZE_T_MAX;
- int result;
-
- if (!asciilib_parse_args_finds("endswith", args, &subobj, &start, &end))
- return NULL;
  if (PyTuple_Check(subobj)) {
  Py_ssize_t i;
  for (i = 0; i < PyTuple_GET_SIZE(subobj); i++) {
- substring = PyTuple_GET_ITEM(subobj, i);
+PyObject *substring = PyTuple_GET_ITEM(subobj, i);
  if (!PyUnicode_Check(substring)) {
  PyErr_Format(PyExc_TypeError,
  "tuple for endswith must only contain str, "
  "not %.100s",
  Py_TYPE(substring)->tp_name);
  return NULL;
  }
- result = tailmatch(self, substring, start, end, +1);
- if (result == -1)
+int result = tailmatch(self, substring, start, end, +1);
+ if (result < 0) {
  return NULL;
+ }
  if (result) {
  Py_RETURN_TRUE;
  }
@@ -13121,9 +13116,10 @@ unicode_endswith(PyObject *self,
  "a tuple of str, not %.100s", Py_TYPE(subobj)->tp_name);
  return NULL;
  }
- result = tailmatch(self, subobj, start, end, +1);
- if (result == -1)
+int result = tailmatch(self, subobj, start, end, +1);
+ if (result < 0) {
  return NULL;
+ }
  return PyBool_FromLong(result);
 }
 
@@ -13576,8 +13572,8 @@ static PyMethodDef unicode_methods[] = {
  UNICODE_SWAPCASE_METHODDEF
  UNICODE_TRANSLATE_METHODDEF
  UNICODE_UPPER_METHODDEF
-{"startswith", (PyCFunction) unicode_startswith, METH_VARARGS, startswith__doc__},
-{"endswith", (PyCFunction) unicode_endswith, METH_VARARGS, endswith__doc__},
+UNICODE_STARTSWITH_METHODDEF
+UNICODE_ENDSWITH_METHODDEF
  UNICODE_REMOVEPREFIX_METHODDEF
  UNICODE_REMOVESUFFIX_METHODDEF
  UNICODE_ISASCII_METHODDEF