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| author | Serhiy Storchaka <storchaka@gmail.com> | 2020-02-12 10:18:59 (GMT) |
|---|---|---|
| committer | GitHub <noreply@github.com> | 2020-02-12 10:18:59 (GMT) |
| commit | 8c579b1cc86053473eb052b76327279476740c9b (patch) | |
| tree | bc99d5f52e1330500216512d1064c2f341b64d89 /Lib/test/test_peepholer.py | |
| parent | 0cc6b5e559b8303b18fdd56c2befd900fe7b5e35 (diff) | |
| download | cpython-8c579b1cc86053473eb052b76327279476740c9b.zip cpython-8c579b1cc86053473eb052b76327279476740c9b.tar.gz cpython-8c579b1cc86053473eb052b76327279476740c9b.tar.bz2 | |
bpo-32856: Optimize the assignment idiom in comprehensions. (GH-16814)
Now `for y in [expr]` in comprehensions is as fast as a simple
assignment `y = expr`.
Diffstat (limited to 'Lib/test/test_peepholer.py')
| -rw-r--r-- | Lib/test/test_peepholer.py | 14 |
1 files changed, 14 insertions, 0 deletions
diff --git a/Lib/test/test_peepholer.py b/Lib/test/test_peepholer.py index 567e6a1..7913e91 100644 --- a/Lib/test/test_peepholer.py +++ b/Lib/test/test_peepholer.py @@ -495,6 +495,20 @@ class TestTranforms(BytecodeTestCase): return 6 self.check_lnotab(f) + def test_assignment_idiom_in_comprehensions(self): + def listcomp(): + return [y for x in a for y in [f(x)]] + self.assertEqual(count_instr_recursively(listcomp, 'FOR_ITER'), 1) + def setcomp(): + return {y for x in a for y in [f(x)]} + self.assertEqual(count_instr_recursively(setcomp, 'FOR_ITER'), 1) + def dictcomp(): + return {y: y for x in a for y in [f(x)]} + self.assertEqual(count_instr_recursively(dictcomp, 'FOR_ITER'), 1) + def genexpr(): + return (y for x in a for y in [f(x)]) + self.assertEqual(count_instr_recursively(genexpr, 'FOR_ITER'), 1) + class TestBuglets(unittest.TestCase): |