Pass a variable between functions within a class
<p>How can I pass a variable returned by a function within a class to another function within that class?<br>
For example (implementing linear regression):</p>

<pre><code>class ForwardPropagation(object):
    def __init__(self, xs, realoutput): 
        self.xs = np.asarray(xs)
        self.realoutput = np.asarray(realoutput)
        self.guess_slope = random.randint(1,10)
        self.guess_b = random.randint(1,10)
        self.guess_output = (self.guess_slope * self.xs) + self.guess_b

    def distance(self):#returns np.array with distance results
        abs_D = self.realoutput - self.guess_output
        D_sqr = abs_D ** 2
        return abs_D, D_sqr

    def error(self):
        sigma = np.sum(D_sqr)
        mean_error = sigma / len(D_sqr)
        return mean_error
</code></pre>

<p>How can I pass the variable D_sqr, which is the squared of my distance function, to the error function? </p>