Issue #28739: f-string expressions no longer accepted as docstrings and
by ast.literal_eval() even if they do not include subexpressions.
diff --git a/Python/ast.c b/Python/ast.c
index 82f4529..217ea14 100644
--- a/Python/ast.c
+++ b/Python/ast.c
@@ -4789,6 +4789,7 @@
typedef struct {
PyObject *last_str;
ExprList expr_list;
+ int fmode;
} FstringParser;
#ifdef NDEBUG
@@ -4807,6 +4808,7 @@
FstringParser_Init(FstringParser *state)
{
state->last_str = NULL;
+ state->fmode = 0;
ExprList_Init(&state->expr_list);
FstringParser_check_invariants(state);
}
@@ -4869,6 +4871,7 @@
struct compiling *c, const node *n)
{
FstringParser_check_invariants(state);
+ state->fmode = 1;
/* Parse the f-string. */
while (1) {
@@ -4960,7 +4963,8 @@
/* If we're just a constant string with no expressions, return
that. */
- if(state->expr_list.size == 0) {
+ if (!state->fmode) {
+ assert(!state->expr_list.size);
if (!state->last_str) {
/* Create a zero length string. */
state->last_str = PyUnicode_FromStringAndSize(NULL, 0);
@@ -4984,11 +4988,6 @@
if (!seq)
goto error;
- /* If there's only one expression, return it. Otherwise, we need
- to join them together. */
- if (seq->size == 1)
- return seq->elements[0];
-
return JoinedStr(seq, LINENO(n), n->n_col_offset, c->c_arena);
error:
diff --git a/Python/compile.c b/Python/compile.c
index 35151cd..0e16075 100644
--- a/Python/compile.c
+++ b/Python/compile.c
@@ -3415,7 +3415,8 @@
compiler_joined_str(struct compiler *c, expr_ty e)
{
VISIT_SEQ(c, expr, e->v.JoinedStr.values);
- ADDOP_I(c, BUILD_STRING, asdl_seq_LEN(e->v.JoinedStr.values));
+ if (asdl_seq_LEN(e->v.JoinedStr.values) != 1)
+ ADDOP_I(c, BUILD_STRING, asdl_seq_LEN(e->v.JoinedStr.values));
return 1;
}