python - How to get the real cube root of a negative number in Python3? -

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python 3.4 seemingly randomly decides whether returns real or complex root of number using ** operator: 

>>> (863.719-2500) -1636.281   >>> -1636.281**(1/3)   -11.783816270504108 >>> (863.719-2500)**(1/3)   (5.891908135252055+10.205084243784958j)

is there way ensure real root when cube rooting rather 1 of complex ones?

in second case cube root getting evaluated first minus sign getting applied, hence real root.

that -1636.281**(1/3) becomes -(1636.281**(1/3)) . , can use similar logic real cubic roots well.

but actually, when doing cubic root of negative numbers complex numbers in python.

>>> -1636.281**(1/3)   -11.783816270504108 >>> (-1636.281)**(1/3) (5.891908135252055+10.205084243784958j)

if want real numbers can add code -

def cube(x):     if x >= 0:         return x**(1/3)     elif x < 0:         return -(abs(x)**(1/3))

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