Pandas Counting Unique Rows : <p>I have a pandas data frame similar to:</p>

<pre><code>ColA ColB
1    1
1    1
1    1
1    2
1    2
2    1
3    2
</code></pre>

<p>I want an output that has the same function as <a href="https://docs.python.org/2/library/collections.html#collections.Counter" rel="noreferrer">Counter</a>.  I need to know how many time each row appears (with all of the columns being the same.</p>

<p>In this case the proper output would be:</p>

<pre><code>ColA ColB Count
1    1    3
1    2    2
2    1    1
3    2    1
</code></pre>

<p>I have tried something of the sort:</p>

<pre><code>df.groupby(['ColA','ColB']).ColA.count()
</code></pre>

<p>but this gives me some ugly output I am having trouble formatting</p>
