diff options
Diffstat (limited to 'numpy/lib')
| -rw-r--r-- | numpy/lib/recfunctions.py | 46 | ||||
| -rw-r--r-- | numpy/lib/tests/test_recfunctions.py | 37 |
2 files changed, 75 insertions, 8 deletions
diff --git a/numpy/lib/recfunctions.py b/numpy/lib/recfunctions.py index 6e257bb3f..c17c39c8a 100644 --- a/numpy/lib/recfunctions.py +++ b/numpy/lib/recfunctions.py @@ -874,16 +874,35 @@ def _get_fields_and_offsets(dt, offset=0): scalar fields in the dtype "dt", including nested fields, in left to right order. """ + + # counts up elements in subarrays, including nested subarrays, and returns + # base dtype and count + def count_elem(dt): + count = 1 + while dt.shape != (): + for size in dt.shape: + count *= size + dt = dt.base + return dt, count + fields = [] for name in dt.names: field = dt.fields[name] - if field[0].names is None: - count = 1 - for size in field[0].shape: - count *= size - fields.append((field[0], count, field[1] + offset)) + f_dt, f_offset = field[0], field[1] + f_dt, n = count_elem(f_dt) + + if f_dt.names is None: + fields.append((np.dtype((f_dt, (n,))), n, f_offset + offset)) else: - fields.extend(_get_fields_and_offsets(field[0], field[1] + offset)) + subfields = _get_fields_and_offsets(f_dt, f_offset + offset) + size = f_dt.itemsize + + for i in range(n): + if i == 0: + # optimization: avoid list comprehension if no subarray + fields.extend(subfields) + else: + fields.extend([(d, c, o + i*size) for d, c, o in subfields]) return fields @@ -948,6 +967,12 @@ def structured_to_unstructured(arr, dtype=None, copy=False, casting='unsafe'): fields = _get_fields_and_offsets(arr.dtype) n_fields = len(fields) + if n_fields == 0 and dtype is None: + raise ValueError("arr has no fields. Unable to guess dtype") + elif n_fields == 0: + # too many bugs elsewhere for this to work now + raise NotImplementedError("arr with no fields is not supported") + dts, counts, offsets = zip(*fields) names = ['f{}'.format(n) for n in range(n_fields)] @@ -1039,6 +1064,9 @@ def unstructured_to_structured(arr, dtype=None, names=None, align=False, if arr.shape == (): raise ValueError('arr must have at least one dimension') n_elem = arr.shape[-1] + if n_elem == 0: + # too many bugs elsewhere for this to work now + raise NotImplementedError("last axis with size 0 is not supported") if dtype is None: if names is None: @@ -1051,7 +1079,11 @@ def unstructured_to_structured(arr, dtype=None, names=None, align=False, raise ValueError("don't supply both dtype and names") # sanity check of the input dtype fields = _get_fields_and_offsets(dtype) - dts, counts, offsets = zip(*fields) + if len(fields) == 0: + dts, counts, offsets = [], [], [] + else: + dts, counts, offsets = zip(*fields) + if n_elem != sum(counts): raise ValueError('The length of the last dimension of arr must ' 'be equal to the number of fields in dtype') diff --git a/numpy/lib/tests/test_recfunctions.py b/numpy/lib/tests/test_recfunctions.py index 0126ccaf8..dc4afe077 100644 --- a/numpy/lib/tests/test_recfunctions.py +++ b/numpy/lib/tests/test_recfunctions.py @@ -248,7 +248,8 @@ class TestRecFunctions(object): # including uniform fields with subarrays unpacked d = np.array([(1, [2, 3], [[ 4, 5], [ 6, 7]]), (8, [9, 10], [[11, 12], [13, 14]])], - dtype=[('x0', 'i4'), ('x1', ('i4', 2)), ('x2', ('i4', (2, 2)))]) + dtype=[('x0', 'i4'), ('x1', ('i4', 2)), + ('x2', ('i4', (2, 2)))]) dd = structured_to_unstructured(d) ddd = unstructured_to_structured(dd, d.dtype) assert_(dd.base is d) @@ -262,6 +263,40 @@ class TestRecFunctions(object): assert_equal(res, np.zeros((10, 6), dtype=int)) + # test nested combinations of subarrays and structured arrays, gh-13333 + def subarray(dt, shape): + return np.dtype((dt, shape)) + + def structured(*dts): + return np.dtype([('x{}'.format(i), dt) for i, dt in enumerate(dts)]) + + def inspect(dt, dtype=None): + arr = np.zeros((), dt) + ret = structured_to_unstructured(arr, dtype=dtype) + backarr = unstructured_to_structured(ret, dt) + return ret.shape, ret.dtype, backarr.dtype + + dt = structured(subarray(structured(np.int32, np.int32), 3)) + assert_equal(inspect(dt), ((6,), np.int32, dt)) + + dt = structured(subarray(subarray(np.int32, 2), 2)) + assert_equal(inspect(dt), ((4,), np.int32, dt)) + + dt = structured(np.int32) + assert_equal(inspect(dt), ((1,), np.int32, dt)) + + dt = structured(np.int32, subarray(subarray(np.int32, 2), 2)) + assert_equal(inspect(dt), ((5,), np.int32, dt)) + + dt = structured() + assert_raises(ValueError, structured_to_unstructured, np.zeros(3, dt)) + + # these currently don't work, but we may make it work in the future + assert_raises(NotImplementedError, structured_to_unstructured, + np.zeros(3, dt), dtype=np.int32) + assert_raises(NotImplementedError, unstructured_to_structured, + np.zeros((3,0), dtype=np.int32)) + def test_field_assignment_by_name(self): a = np.ones(2, dtype=[('a', 'i4'), ('b', 'f8'), ('c', 'u1')]) newdt = [('b', 'f4'), ('c', 'u1')] |