diff --git a/py/objstr.c b/py/objstr.c
index 3a4b0b97f37ebe44defd8415bda0234bdd42b33b..b5f40551f336e2be30fcfee6f4d48f9836c02671 100644
--- a/py/objstr.c
+++ b/py/objstr.c
@@ -38,6 +38,7 @@
#include "runtime.h"
#include "pfenv.h"
#include "objstr.h"
+#include "objlist.h"
STATIC mp_obj_t str_modulo_format(mp_obj_t pattern, uint n_args, const mp_obj_t *args);
const mp_obj_t mp_const_empty_bytes;
@@ -483,6 +484,69 @@ STATIC mp_obj_t str_split(uint n_args, const mp_obj_t *args) {
return res;
}
+STATIC mp_obj_t str_rsplit(uint n_args, const mp_obj_t *args) {
+ if (n_args < 3) {
+ // If we don't have split limit, it doesn't matter from which side
+ // we split.
+ return str_split(n_args, args);
+ }
+ const mp_obj_type_t *self_type = mp_obj_get_type(args[0]);
+ mp_obj_t sep = args[1];
+ GET_STR_DATA_LEN(args[0], s, len);
+
+ machine_int_t splits = mp_obj_get_int(args[2]);
+ machine_int_t org_splits = splits;
+ // Preallocate list to the max expected # of elements, as we
+ // will fill it from the end.
+ mp_obj_list_t *res = mp_obj_new_list(splits + 1, NULL);
+ int idx = splits;
+
+ if (sep == mp_const_none) {
+ // TODO
+ assert(0);
+ } else {
+ uint sep_len;
+ const char *sep_str = mp_obj_str_get_data(sep, &sep_len);
+
+ if (sep_len == 0) {
+ nlr_raise(mp_obj_new_exception_msg(&mp_type_ValueError, "empty separator"));
+ }
+
+ const byte *beg = s;
+ const byte *last = s + len;
+ for (;;) {
+ s = last - sep_len;
+ for (;;) {
+ if (splits == 0 || s < beg) {
+ break;
+ } else if (memcmp(s, sep_str, sep_len) == 0) {
+ break;
+ }
+ s--;
+ }
+ if (s < beg || splits == 0) {
+ res->items[idx] = str_new(self_type, beg, last - beg);
+ break;
+ }
+ res->items[idx--] = str_new(self_type, s + sep_len, last - s - sep_len);
+ last = s;
+ if (splits > 0) {
+ splits--;
+ }
+ }
+ if (idx != 0) {
+ // We split less parts than split limit, now go cleanup surplus
+ int used = org_splits + 1 - idx;
+ memcpy(res->items, &res->items[idx], used * sizeof(mp_obj_t));
+ mp_seq_clear(res->items, used, res->alloc, sizeof(*res->items));
+ res->len = used;
+ }
+ }
+
+ return res;
+}
+
+
STATIC mp_obj_t str_finder(uint n_args, const mp_obj_t *args, machine_int_t direction, bool is_index) {
assert(2 <= n_args && n_args <= 4);
assert(MP_OBJ_IS_STR(args[0]));
@@ -1460,6 +1524,7 @@ STATIC MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(str_index_obj, 2, 4, str_index);
STATIC MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(str_rindex_obj, 2, 4, str_rindex);
STATIC MP_DEFINE_CONST_FUN_OBJ_2(str_join_obj, str_join);
STATIC MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(str_split_obj, 1, 3, str_split);
+STATIC MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(str_rsplit_obj, 1, 3, str_rsplit);
STATIC MP_DEFINE_CONST_FUN_OBJ_2(str_startswith_obj, str_startswith);
STATIC MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(str_strip_obj, 1, 2, str_strip);
STATIC MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(str_lstrip_obj, 1, 2, str_lstrip);
@@ -1483,6 +1548,7 @@ STATIC const mp_map_elem_t str_locals_dict_table[] = {
{ MP_OBJ_NEW_QSTR(MP_QSTR_rindex), (mp_obj_t)&str_rindex_obj },
{ MP_OBJ_NEW_QSTR(MP_QSTR_join), (mp_obj_t)&str_join_obj },
{ MP_OBJ_NEW_QSTR(MP_QSTR_split), (mp_obj_t)&str_split_obj },
+ { MP_OBJ_NEW_QSTR(MP_QSTR_rsplit), (mp_obj_t)&str_rsplit_obj },
{ MP_OBJ_NEW_QSTR(MP_QSTR_startswith), (mp_obj_t)&str_startswith_obj },
{ MP_OBJ_NEW_QSTR(MP_QSTR_strip), (mp_obj_t)&str_strip_obj },
{ MP_OBJ_NEW_QSTR(MP_QSTR_lstrip), (mp_obj_t)&str_lstrip_obj },
diff --git a/py/qstrdefs.h b/py/qstrdefs.h
index 1679d8b39c3bf87ff60a16dad4b306afc05639c8..ca300101203df4e4f1adedd29e0030efddb25015 100644
--- a/py/qstrdefs.h
+++ b/py/qstrdefs.h
@@ -236,6 +236,7 @@ Q(find)
Q(rfind)
Q(rindex)
Q(split)
+Q(rsplit)
Q(startswith)
Q(replace)
Q(partition)
diff --git a/tests/basics/string_rsplit.py b/tests/basics/string_rsplit.py
new file mode 100644
index 0000000000000000000000000000000000000000..cc6c0fd062c38d361cd0026901f86a1184d5cf42
--- /dev/null
+++ b/tests/basics/string_rsplit.py
@@ -0,0 +1,42 @@
+# default separator (whitespace)
+print("a b".rsplit())
+#print(" a b ".rsplit(None))
+#print(" a b ".rsplit(None, 1))
+#print(" a b ".rsplit(None, 2))
+#print(" a b c ".rsplit(None, 1))
+#print(" a b c ".rsplit(None, 0))
+#print(" a b c ".rsplit(None, -1))
+
+# empty separator should fail
+try:
+ "abc".rsplit('')
+except ValueError:
+ print("ValueError")
+
+# non-empty separator
+print("abc".rsplit("a"))
+print("abc".rsplit("b"))
+print("abc".rsplit("c"))
+print("abc".rsplit("z"))
+print("abc".rsplit("ab"))
+print("abc".rsplit("bc"))
+print("abc".rsplit("abc"))
+print("abc".rsplit("abcd"))
+print("abcabc".rsplit("bc"))
+print("abcabc".rsplit("bc", 0))
+print("abcabc".rsplit("bc", 1))
+print("abcabc".rsplit("bc", 2))
+
+print("10/11/12".rsplit("/", 1))
+print("10/11/12".rsplit("/", 2))
+print("10/11/12".rsplit("/", 3))
+print("10/11/12".rsplit("/", 4))
+print("10/11/12".rsplit("/", 5))
+
+print("/*10/*11/*12/*".rsplit("/*", 1))
+print("/*10/*11/*12/*".rsplit("/*", 2))
+print("/*10/*11/*12/*".rsplit("/*", 3))
+print("/*10/*11/*12/*".rsplit("/*", 4))
+print("/*10/*11/*12/*".rsplit("/*", 5))
+
+print(b"abcabc".rsplit(b"bc", 2))