New submission from Cyker Way <[email protected]>:
Acccording to: https://docs.python.org/3/library/functions.html#float
> If the argument is outside the range of a Python float, an OverflowError
> will be raised.
It is well known that the maximum value in IEEE 754 binary64 format is:
>>> M = ((1<<53)-1)<<(1023-52)
...
So `(M+1)` will be out of range. But `float(M+1)` gives me:
>>> float(M+1)
1.7976931348623157e+308
No OverflowError is thrown. Contrast this with:
>>> float(M+M)
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
OverflowError: int too large to convert to float
In another text:
https://docs.python.org/3/tutorial/floatingpoint.html#representation-error
> ...Almost all machines today (November 2000) use IEEE-754 floating point
> arithmetic, and almost all platforms map Python floats to IEEE-754 “double
> precision”...
Is Python not following IEEE 754 binary64 format or something missing here?
----------
components: Interpreter Core
messages: 409143
nosy: cykerway
priority: normal
severity: normal
status: open
title: float(x) with large x not raise OverflowError
type: behavior
versions: Python 3.10, Python 3.9
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Python tracker <[email protected]>
<https://bugs.python.org/issue46173>
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