8000 Fix type object signature when both __new__ and __init__ present by msullivan · Pull Request #5642 · python/mypy · GitHub
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Fix type object signature when both __new__ and __init__ present #5642

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Merged
merged 7 commits into from
Sep 20, 2018
Merged

Fix type object signature when both __new__ and __init__ present #5642

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b06d60a
Fix type object signature when both __new__ and __init__ present
msullivan Sep 19, 2018
67dd369
Merge branch 'master' into new_over_init
msullivan Sep 19, 2018
162e7e7
tweak the test
msullivan Sep 19, 2018
ef0cfc3
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msullivan Sep 19, 2018
39797b8
oops
msullivan Sep 19, 2018
6bb958d
Merge branch 'master' into new_over_init
msullivan Sep 20, 2018
23ce621
oops
msullivan Sep 20, 2018
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tweak the test
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@msullivan
msullivan committed Sep 19, 2018
commit 162e7e7fdf3090898086d49b21690769c7cbc5e9
5 changes: 2 additions & 3 deletions test-data/unit/check-classes.test
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Expand Up @@ -5124,11 +5124,10 @@ class A:
pass

class B(A):
def __new__(cls) -> 'B':
...
def __new__(cls) -> int:
return 10

B()
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But at runtime in CPython this is an error:

$ Traceback (most recent call last):
  File "_.py", line 9, in <module>
    b = B()
TypeError: __init__() missing 1 required positional argument: 'x'

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Oh, hm:
The original bug example had the __new__ call return an int, which works because __init__ isn't called if it isn't a subclass.

reveal_type(B) # E: Revealed type is 'def () -> __main__.B'

[case testNewAndInit2]
from typing import Any
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