Propagate exceptions in sequence::size() (#2076)
diff --git a/include/pybind11/pytypes.h b/include/pybind11/pytypes.h
index 4003d69..63cbf2e 100644
--- a/include/pybind11/pytypes.h
+++ b/include/pybind11/pytypes.h
@@ -1242,7 +1242,12 @@
class sequence : public object {
public:
PYBIND11_OBJECT_DEFAULT(sequence, object, PySequence_Check)
- size_t size() const { return (size_t) PySequence_Size(m_ptr); }
+ size_t size() const {
+ ssize_t result = PySequence_Size(m_ptr);
+ if (result == -1)
+ throw error_already_set();
+ return (size_t) result;
+ }
bool empty() const { return size() == 0; }
detail::sequence_accessor operator[](size_t index) const { return {*this, index}; }
detail::item_accessor operator[](handle h) const { return object::operator[](h); }
diff --git a/tests/test_sequences_and_iterators.cpp b/tests/test_sequences_and_iterators.cpp
index 87ccf99..05f999b 100644
--- a/tests/test_sequences_and_iterators.cpp
+++ b/tests/test_sequences_and_iterators.cpp
@@ -319,6 +319,9 @@
return l;
});
+ // test_sequence_length: check that Python sequences can be converted to py::sequence.
+ m.def("sequence_length", [](py::sequence seq) { return seq.size(); });
+
// Make sure that py::iterator works with std algorithms
m.def("count_none", [](py::object o) {
return std::count_if(o.begin(), o.end(), [](py::handle h) { return h.is_none(); });
diff --git a/tests/test_sequences_and_iterators.py b/tests/test_sequences_and_iterators.py
index 6bd1606..d839dbe 100644
--- a/tests/test_sequences_and_iterators.py
+++ b/tests/test_sequences_and_iterators.py
@@ -100,6 +100,25 @@
assert cstats.move_assignments == 0
+def test_sequence_length():
+ """#2076: Exception raised by len(arg) should be propagated """
+ class BadLen(RuntimeError):
+ pass
+
+ class SequenceLike():
+ def __getitem__(self, i):
+ return None
+
+ def __len__(self):
+ raise BadLen()
+
+ with pytest.raises(BadLen):
+ m.sequence_length(SequenceLike())
+
+ assert m.sequence_length([1, 2, 3]) == 3
+ assert m.sequence_length("hello") == 5
+
+
def test_map_iterator():
sm = m.StringMap({'hi': 'bye', 'black': 'white'})
assert sm['hi'] == 'bye'