Variables and function
<p>Hey all, is it possible to call a function value instead of calling the whole function?As, if i call the whole function, it will run unnecessarily which i do not want.
For example:</p>

<pre><code>def main():
    # Inputing the x-value for the first start point of the line
    start_point_x_1()
    # Inputing the x-value for the 2nd end point of the line
    end_point_x_2()
    # The first output point calculated and printed
    first_calculated_point()

def start_point_x_1():
    return raw_input("Enter the x- value for the 1st " +
                        "start point for the line.\n")

def end_point_x_2():
    return raw_input("Enter the x- value for the 2nd " +
                      "end point for the line.\n")

def first_calculated_point():
    x0 = int(start_point_x_1())
    a  = int(end_point_x_2()) - int(start_point_x_1())
    lamda_0 = 0
    x = x0 + (lamda_0)*a

main()
</code></pre>

<p>The code above works but when i reach the function <code>first_calculated_point</code> and when i calculate <code>x0</code>, the function <code>start_point_x_1()</code> runs again.I tried storing the function like ' for example <code>x1 = raw_input("Enter the x- value for the 1st " + "start point for the line.\n")</code> under the function <code>start_point_x_1()</code> but when i call the variable <code>x1</code> at <code>x0 = x1</code>, they said <code>x1</code> is not defined. Is there any way to store the value of the function and call it instead of calling the whole function?</p>
