To whom it may concern https://docs.python.org/3/library/cmath.html#module-cmath Page says this means that the sign of the result is the same as the sign of x.imag, even when x.imag is zero. But I think *'x.real' *is right. Sincerely, !~*!~*!~*!~*!~*!~*!~*!~*!~*!~*!~*!~*!~*!~*!~*!~*!~*!~*!~*!~*!~*!~*!~*!~* Name : YoungJun Lee Cell Phone : +82-10-6657-3411 Blog: https://hackedbypsychedelphia.blogspot.com/ !~*!~*!~*!~*!~*!~*!~*!~*!~*!~*!~*!~*!~*!~*!~*!~*!~*!~*!~*!~*!~*!~*!~*!~*