Loop over and editing the items in a list after looping over some input data
<p>Why can i only get the [-1.0,0.0,1.0,2.0,3.0], instead of 
[0.0,1.0,2.0,3.0,4.0]
[-2.0,-1.0,0.0,1.0,2.0]
[-1.0,0.0,1.0,2.0,3.0], thank you</p>

<pre><code>V = [1,2,3,4,5]
f = open('Qin.txt')             # values in Qin.txt: 1
    for line in iter(f):                             3
    Z = float(line)                                  2

    c = []
    for i in range(len(V)):
    c.append(V[i]-Z)

    print c
</code></pre>
