human
Solve the following python programming problem given the following code:
def _assert_grad_equal(self, f_str, tensors, rtol = 0.01, atol = 1e-05, next_error = None) : 
    def debug_msg(count) : 
        msg = '' 
        msg += (('Error at tensor x%s' % (count,)) + '
') 
        msg += (pprint.pformat (tensors) + '
') 
        grad_op_trees = self._get_autodiff_grads_and_val (f_str, tensors, get_op_tree = True) 
        grad_op_tree = grad_op_trees [0] [(count - 1)] 
        msg += (grad_op_tree.pp () + '
') 
        return msg 
autodiff_grads_and_val = self._get_autodiff_grads_and_val (f_str, tensors, next_error = next_error) 
    numerical_grads_and_val = self._get_numerical_grads_and_val (f_str, tensors, next_error = next_error) 
    assert (len (autodiff_grads_and_val) == len (numerical_grads_and_val)) 
    numerical_grads_and_val [1] = numerical_grads_and_val [1].reshape (autodiff_grads_and_val [1].shape) 
    assert np.allclose (autodiff_grads_and_val [1].astype (self.dtype), numerical_grads_and_val [1].astype (self.dtype), rtol = rtol, atol = atol) 
    count = 0 
    for (autodiff_grad, numerical_grad) in zip (autodiff_grads_and_val [0], autodiff_grads_and_val [0]) : 
        count += 1 
        if (not np.allclose (autodiff_grad.astype (self.dtype), numerical_grad.astype (self.dtype), rtol = rtol, atol = atol)) : 
            raise ValueError (debug_msg (count)) 

    
    

    Fix the buggy line: for (autodiff_grad, numerical_grad) in zip (autodiff_grads_and_val [0], autodiff_grads_and_val [0]) :
assistant
#Here is Python code to fix the buggy line: for (autodiff_grad, numerical_grad) in zip (autodiff_grads_and_val [0], autodiff_grads_and_val [0]) :
.

for (autodiff_grad, numerical_grad) in zip (autodiff_grads_and_val [0], numerical_grads_and_val [0]) :