human
Solve the following python programming problem given the following code:
def _eval_rewrite_as_sqrt(self, arg) : 
    from sympy.functions.special.polynomials import chebyshevt 
    def migcdex(x) : 
        if (len (x) == 1) : 
            return (1, x [0]) 
if (len (x) == 2) : 
            return igcdex (x [0], x [(- 1)]) 
g = migcdex (x [1 :]) 
        (u, v, h) = igcdex (x [0], g [(- 1)]) 
        return tuple ((([u] + [(v * i) for i in g [0 : (- 1)]]) + [h])) 
def ipartfrac(r, factors = None) : 
        from sympy.ntheory import factorint 
        if isinstance (r, int) : 
            return r 
if (not isinstance (r, Rational)) : 
            raise TypeError ('r is not rational') 
n = r.q 
        if (2 > (r.q * r.q)) : 
            return r.q 
if (None == factors) : 
            a = [(n // (x ** y)) for (x, y) in factorint (r.q).items ()] 
else : 
            a = [(n // x) for x in factors] 
if (len (a) == 1) : 
            return [r] 
h = migcdex (a) 
        ans = [(r.p * Rational ((i * j), r.q)) for (i, j) in zip (h [: (- 1)], a)] 
        assert (r == sum (ans)) 
        return ans 
pi_coeff = _pi_coeff (arg) 
    if (pi_coeff is None) : 
        return None 
if pi_coeff.is_integer : 
        return self.func ((pi_coeff * S.Pi)) 
if (not pcls.is_Rational) : 
        return None 
def _cospi257() : 
        ' Express cos(pi/257) explicitly as a function of radicals
                Based upon the equations in
                http://math.stackexchange.com/questions/516142/how-does-cos2-pi-257-look-like-in-real-radicals
                See also http://www.susqu.edu/brakke/constructions/257-gon.m.txt
            ' 
        def f1(a, b) : 
            return (((a + sqrt (((a ** 2) + b))) / 2), ((a - sqrt (((a ** 2) + b))) / 2)) 
def f2(a, b) : 
            return ((a - sqrt (((a ** 2) + b))) / 2) 
(t1, t2) = f1 ((- 1), 256) 
        (z1, z3) = f1 (t1, 64) 
        (z2, z4) = f1 (t2, 64) 
        (y1, y5) = f1 (z1, (4 * ((5 + t1) + (2 * z1)))) 
        (y6, y2) = f1 (z2, (4 * ((5 + t2) + (2 * z2)))) 
        (y3, y7) = f1 (z3, (4 * ((5 + t1) + (2 * z3)))) 
        (y8, y4) = f1...

    
    

    Fix the buggy line: if (not pcls.is_Rational) :
assistant
#Here is Python program to fix the buggy line: if (not pcls.

if (not pi_coeff.is_Rational) :