Issue #6081: Add str.format_map. str.format_map(mapping) is similar to str.format(**mapping), except mapping does not get converted to a dict.

2 files changed, 16 insertions, 1 deletions

diff --git a/Objects/stringlib/string_format.h b/Objects/stringlib/string_format.h
index 126c870..5205aa9 100644
--- a/Objects/stringlib/string_format.h
+++ b/Objects/stringlib/string_format.h
@@ -499,7 +499,11 @@ get_field_object(SubString *input, PyObject *args, PyObject *kwargs,
         PyObject *key = SubString_new_object(&first);
         if (key == NULL)
             goto error;
-        if ((kwargs == NULL) || (obj = PyDict_GetItem(kwargs, key)) == NULL) {
+
+        /* Use PyObject_GetItem instead of PyDict_GetItem because this
+           code is no longer just used with kwargs. It might be passed
+           a non-dict when called through format_map. */
+        if ((kwargs == NULL) || (obj = PyObject_GetItem(kwargs, key)) == NULL) {
             PyErr_SetObject(PyExc_KeyError, key);
             Py_DECREF(key);
             goto error;
@@ -1039,6 +1043,11 @@ do_string_format(PyObject *self, PyObject *args, PyObject *kwargs)
     return build_string(&input, args, kwargs, recursion_depth, &auto_number);
 }
 
+static PyObject *
+do_string_format_map(PyObject *self, PyObject *obj)
+{
+    return do_string_format(self, NULL, obj);
+}
 
 
 /************************************************************************/
diff --git a/Objects/unicodeobject.c b/Objects/unicodeobject.c
index 17dc27e..b67b8f9 100644
--- a/Objects/unicodeobject.c
+++ b/Objects/unicodeobject.c
@@ -9028,6 +9028,11 @@ PyDoc_STRVAR(format__doc__,
 \n\
 ");
 
+PyDoc_STRVAR(format_map__doc__,
+             "S.format_map(mapping) -> str\n\
+\n\
+");
+
 static PyObject *
 unicode__format__(PyObject* self, PyObject* args)
 {
@@ -9109,6 +9114,7 @@ static PyMethodDef unicode_methods[] = {
     {"isprintable", (PyCFunction) unicode_isprintable, METH_NOARGS, isprintable__doc__},
     {"zfill", (PyCFunction) unicode_zfill, METH_VARARGS, zfill__doc__},
     {"format", (PyCFunction) do_string_format, METH_VARARGS | METH_KEYWORDS, format__doc__},
+    {"format_map", (PyCFunction) do_string_format_map, METH_O, format_map__doc__},
     {"__format__", (PyCFunction) unicode__format__, METH_VARARGS, p_format__doc__},
     {"maketrans", (PyCFunction) unicode_maketrans,
      METH_VARARGS | METH_STATIC, maketrans__doc__},