#9418: first step of moving private string methods to _string module.

Lib/string.py

@@ -14,6 +14,8 @@ printable -- a string containing all ASCII characters considered printable
 
 """
 
+import _string
+
 # Some strings for ctype-style character classification
 whitespace = ' \t\n\r\v\f'
 ascii_lowercase = 'abcdefghijklmnopqrstuvwxyz'
@@ -170,8 +172,8 @@ class Template(metaclass=_TemplateMetaclass):
 # The hard parts are reused from the C implementation.  They're exposed as "_"
 # prefixed methods of str.
 
-# The overall parser is implemented in str._formatter_parser.
-# The field name parser is implemented in str._formatter_field_name_split
+# The overall parser is implemented in _string.formatter_parser.
+# The field name parser is implemented in _string.formatter_field_name_split
 
 class Formatter:
     def format(self, format_string, *args, **kwargs):
@@ -251,7 +253,7 @@ class Formatter:
     # if field_name is not None, it is looked up, formatted
     #  with format_spec and conversion and then used
     def parse(self, format_string):
-        return format_string._formatter_parser()
+        return _string.formatter_parser(format_string)
 
 
     # given a field_name, find the object it references.
@@ -260,7 +262,7 @@ class Formatter:
     #  used_args:    a set of which args have been used
     #  args, kwargs: as passed in to vformat
     def get_field(self, field_name, args, kwargs):
-        first, rest = field_name._formatter_field_name_split()
+        first, rest = _string.formatter_field_name_split(field_name)
 
         obj = self.get_value(first, args, kwargs)
 

Misc/NEWS

@@ -10,6 +10,9 @@ What's New in Python 3.2 Beta 1?
 Core and Builtins
 -----------------
 
+- Issue #9418: Moved private string methods ``_formatter_parser`` and
+  ``_formatter_field_name_split`` into a new ``_string`` module.
+
 - Issue #9992: Remove PYTHONFSENCODING environment variable.
 
 Library

Modules/config.c.in

@@ -29,6 +29,7 @@ extern PyObject* PyInit_imp(void);
 extern PyObject* PyInit_gc(void);
 extern PyObject* PyInit__ast(void);
 extern PyObject* _PyWarnings_Init(void);
+extern PyObject* PyInit__string(void);
 
 struct _inittab _PyImport_Inittab[] = {
 
@@ -54,6 +55,9 @@ struct _inittab _PyImport_Inittab[] = {
     /* This lives in _warnings.c */
     {"_warnings", _PyWarnings_Init},
 
+    /* This lives in Objects/unicodeobject.c */
+    {"_string", PyInit__string},
+
     /* Sentinel */
     {0, 0}
 };

Objects/stringlib/string_format.h

@@ -1180,7 +1180,7 @@ static PyTypeObject PyFormatterIter_Type = {
    describing the parsed elements.  It's a wrapper around
    stringlib/string_format.h's MarkupIterator */
 static PyObject *
-formatter_parser(STRINGLIB_OBJECT *self)
+formatter_parser(PyObject *ignored, STRINGLIB_OBJECT *self)
 {
     formatteriterobject *it;
 
@@ -1315,7 +1315,7 @@ static PyTypeObject PyFieldNameIter_Type = {
    field_name_split.  The iterator it returns is a
    FieldNameIterator */
 static PyObject *
-formatter_field_name_split(STRINGLIB_OBJECT *self)
+formatter_field_name_split(PyObject *ignored, STRINGLIB_OBJECT *self)
 {
     SubString first;
     Py_ssize_t first_idx;

Objects/unicodeobject.c

@@ -8968,8 +8968,6 @@ static PyMethodDef unicode_methods[] = {
     {"zfill", (PyCFunction) unicode_zfill, METH_VARARGS, zfill__doc__},
     {"format", (PyCFunction) do_string_format, METH_VARARGS | METH_KEYWORDS, format__doc__},
     {"__format__", (PyCFunction) unicode__format__, METH_VARARGS, p_format__doc__},
-    {"_formatter_field_name_split", (PyCFunction) formatter_field_name_split, METH_NOARGS},
-    {"_formatter_parser", (PyCFunction) formatter_parser, METH_NOARGS},
     {"maketrans", (PyCFunction) unicode_maketrans,
      METH_VARARGS | METH_STATIC, maketrans__doc__},
     {"__sizeof__", (PyCFunction) unicode__sizeof__, METH_NOARGS, sizeof__doc__},
@@ -10170,6 +10168,36 @@ PyUnicode_AsUnicodeCopy(PyObject *object)
     return copy;
 }
 
+/* A _string module, to export formatter_parser and formatter_field_name_split
+   to the string.Formatter class implemented in Python. */
+
+static PyMethodDef _string_methods[] = {
+    {"formatter_field_name_split", (PyCFunction) formatter_field_name_split,
+     METH_O, PyDoc_STR("split the argument as a field name")},
+    {"formatter_parser", (PyCFunction) formatter_parser,
+     METH_O, PyDoc_STR("parse the argument as a format string")},
+    {NULL, NULL}
+};
+
+static struct PyModuleDef _string_module = {
+    PyModuleDef_HEAD_INIT,
+    "_string",
+    PyDoc_STR("string helper module"),
+    0,
+    _string_methods,
+    NULL,
+    NULL,
+    NULL,
+    NULL
+};
+
+PyMODINIT_FUNC
+PyInit__string(void)
+{
+    return PyModule_Create(&_string_module);
+}
+
+
 #ifdef __cplusplus
 }
 #endif

PC/config.c

@@ -62,6 +62,7 @@ extern PyObject* PyInit__io(void);
 extern PyObject* PyInit__pickle(void);
 extern PyObject* PyInit_atexit(void);
 extern PyObject* _PyWarnings_Init(void);
+extern PyObject* PyInit__string(void);
 
 /* tools/freeze/makeconfig.py marker for additional "extern" */
 /* -- ADDMODULE MARKER 1 -- */
@@ -147,6 +148,7 @@ struct _inittab _PyImport_Inittab[] = {
     {"builtins", NULL},
     {"sys", NULL},
     {"_warnings", _PyWarnings_Init},
+    {"_string", PyInit__string},
 
     {"_io", PyInit__io},
     {"_pickle", PyInit__pickle},