diff options
Diffstat (limited to 'numpy/random')
| -rw-r--r-- | numpy/random/bit_generator.pyx | 11 | ||||
| -rw-r--r-- | numpy/random/tests/test_seed_sequence.py | 28 |
2 files changed, 37 insertions, 2 deletions
diff --git a/numpy/random/bit_generator.pyx b/numpy/random/bit_generator.pyx index f145ec13d..3c52a9933 100644 --- a/numpy/random/bit_generator.pyx +++ b/numpy/random/bit_generator.pyx @@ -382,13 +382,22 @@ cdef class SeedSequence(): ------- entropy_array : 1D uint32 array """ - # Convert run-entropy, program-entropy, and the spawn key into uint32 + # Convert run-entropy and the spawn key into uint32 # arrays and concatenate them. # We MUST have at least some run-entropy. The others are optional. assert self.entropy is not None run_entropy = _coerce_to_uint32_array(self.entropy) spawn_entropy = _coerce_to_uint32_array(self.spawn_key) + if len(spawn_entropy) > 0 and len(run_entropy) < self.pool_size: + # Explicitly fill out the entropy with 0s to the pool size to avoid + # conflict with spawn keys. We changed this in 1.19.0 to fix + # gh-16539. In order to preserve stream-compatibility with + # unspawned SeedSequences with small entropy inputs, we only do + # this when a spawn_key is specified. + diff = self.pool_size - len(run_entropy) + run_entropy = np.concatenate( + [run_entropy, np.zeros(diff, dtype=np.uint32)]) entropy_array = np.concatenate([run_entropy, spawn_entropy]) return entropy_array diff --git a/numpy/random/tests/test_seed_sequence.py b/numpy/random/tests/test_seed_sequence.py index fe23680ed..f08cf80fa 100644 --- a/numpy/random/tests/test_seed_sequence.py +++ b/numpy/random/tests/test_seed_sequence.py @@ -1,5 +1,5 @@ import numpy as np -from numpy.testing import assert_array_equal +from numpy.testing import assert_array_equal, assert_array_compare from numpy.random import SeedSequence @@ -52,3 +52,29 @@ def test_reference_data(): assert_array_equal(state, expected) state64 = ss.generate_state(len(expected64), dtype=np.uint64) assert_array_equal(state64, expected64) + + +def test_zero_padding(): + """ Ensure that the implicit zero-padding does not cause problems. + """ + # Ensure that large integers are inserted in little-endian fashion to avoid + # trailing 0s. + ss0 = SeedSequence(42) + ss1 = SeedSequence(42 << 32) + assert_array_compare( + np.not_equal, + ss0.generate_state(4), + ss1.generate_state(4)) + + # Ensure backwards compatibility with the original 0.17 release for small + # integers and no spawn key. + expected42 = np.array([3444837047, 2669555309, 2046530742, 3581440988], + dtype=np.uint32) + assert_array_equal(SeedSequence(42).generate_state(4), expected42) + + # Regression test for gh-16539 to ensure that the implicit 0s don't + # conflict with spawn keys. + assert_array_compare( + np.not_equal, + SeedSequence(42, spawn_key=(0,)).generate_state(4), + expected42) |