complexes.py 文件源码

def eval(cls, arg):
        if not arg.is_Atom:
            c, arg_ = factor_terms(arg).as_coeff_Mul()
            if arg_.is_Mul:
                arg_ = Mul(*[a if (sign(a) not in (-1, 1)) else
                    sign(a) for a in arg_.args])
            arg_ = sign(c)*arg_
        else:
            arg_ = arg
        if arg_.atoms(AppliedUndef):
            return
        x, y = re(arg_), im(arg_)
        rv = atan2(y, x)
        if rv.is_number:
            return rv
        if arg_ != arg:
            return cls(arg_, evaluate=False)