Adding reverse method for strings

Lib/test/string_tests.py

@@ -1085,6 +1085,12 @@ def test_title(self):
         self.checkequal('Getint', "getInt", 'title')
         self.checkraises(TypeError, 'hello', 'title', 42)
 
+    def test_reverse(self):
+        self.checkequal('', '', 'reverse')
+        self.checkequal('Hello', 'olleH', 'reverse')
+        self.checkequal('Reversed this string', "gnirts siht desreveR", 'reverse')
+        self.checkraises(TypeError, 'hello', 'reverse', 42)
+
     def test_splitlines(self):
         self.checkequal(['abc', 'def', '', 'ghi'], "abc\ndef\n\rghi", 'splitlines')
         self.checkequal(['abc', 'def', '', 'ghi'], "abc\ndef\n\r\nghi", 'splitlines')

Objects/unicodeobject.c

@@ -11060,6 +11060,34 @@ replace(PyObject *self, PyObject *str1,
     return NULL;
 }
 
+// asdf
+static PyObject *
+reverse(PyObject *string) 
+{
+    if (ensure_unicode(string) < 0)
+        return NULL;
+
+    Py_ssize_t length = PyUnicode_GET_LENGTH(string);
+    PyObject* reversed = PyUnicode_New(length, PyUnicode_MAX_CHAR_VALUE(string));
+
+    if (reversed == NULL) {
+        return NULL;
+    }
+
+    for (Py_ssize_t i = 0; i < length; i++) {
+        Py_UCS4 ch = PyUnicode_READ_CHAR(string, length - 1 - i);
+        PyUnicode_WriteChar(reversed, i, ch);
+    }
+
+    return reversed;
+}
+
+static PyObject *
+unicode_reverse_impl(PyObject *self)
+{
+    return reverse(self);
+}
+
 /* --- Unicode Object Methods --------------------------------------------- */
 
 /*[clinic input]