Complex exponentiation doesn't work as expected:

```
>>> (-1) ** 0.5
(6.123233995736766e-17+1j)
```

I think the issue is linked with this part of the code:
https://github.com/python/cpython/blob/32bd68c839adb7b42af12366ab0892303115d1d1/Objects/complexobject.c#L142-L151

What do you mean? It works as I expected.  Can you explain what you expected, and why?

Before replying please read:

https://docs.python.org/3/faq/design.html#why-are-floating-point-calculations-so-inaccurate

https://duckduckgo.com/?q=python+why+are+floating+point+so+inaccurate

Sorry Nathan, I worded my first response awkwardly, of course mathematically we should expect a result of 1j, by why do you expect it in a floating point calculation? Do you have an alternative?

(I promise this is my last comment until you have had a chance to reply.)

It is the same "gotcha" as

>>> math.cos(math.pi/2)
6.123233995736766e-17

You can expect that cos(π/2) is exactly 0, but floating point value math.pi is only an approximation of the π number. The difference between math.pi and exact value of π leads to non-zero result of cos(math.pi/2).

FWIW, if you're specifically interested in complex square roots rather than powers in general, I'd recommend using `cmath.sqrt(value)` rather than `value**0.5` - there are fewer intermediate steps involved in computing `cmath.sqrt`, and the returned value will in general be a bit more accurate, and better defined in corner cases. (And probably slightly faster too, in the rare situations where that matters.)