title: How to check if two keys in dictionary hold the same value
body: <p>This seems like such an obvious thing that I feel like I'm missing out on something, but how do you find out if two different keys in the same dictionary have the exact same value? For example, if you have the dictionary <code>test</code> with the keys <code>a</code>, <code>b</code>, and <code>c</code> and the keys <code>a</code> and <code>b</code> both have the value of 10, how would you figure that out? (For the point of the question, please assume a large number of keys, say 100, and you have no knowledge of how many duplicates there are, if there are multiple sets of duplicates, or if there are duplicates at all). Thanks.</p>