Why is the '+' returning the 'wrong' value in my function?
<p>Having problems with the output of function I made. Can't work out why the '+' don't work, yet all the others are fine.</p>

<pre><code>def operation(val1, val2, oper):
    if oper == '*':
        return val1 * val2
    elif oper == '+':
        return val1 + val1
    elif oper == '-':
        return val1 - val2
    elif oper == '/':
        return val1 / val2
    else:
        raise Exception("Non-legal operation")

#outputs 368.0
print 345.0 + 23.0
#outputs 690.0 - why!?
print operation(345.0, 23.0, '+')
</code></pre>

<p>If someone could explain to me where I've messed up, it would be greatly appreciated!</p>
