class with changing parameters
<p>I want to define a Python class that accepts different variables as input. However I only want to declare one of them when calling the class, because the variables determine each other and in different situations I have different inputs at hand. So it should be something like a class price that I call as:</p>

<pre><code>foo = price(dollar=10)  
bar = price(euro=20)
</code></pre>

<p>and I have a function inside the class that takes the different currencies and translates them into each other.
How do I do that?</p>
