Pandas cumulative count : <p>I have a data frame like this:</p>

<pre><code>0        04:10  obj1
1        04:10  obj1
2        04:11  obj1
3        04:12  obj2
4        04:12  obj2
5        04:12  obj1
6        04:13  obj2
</code></pre>

<p>Wanted to get a cumulative count for all the objects like this:</p>

<pre><code>idx      time   object   obj1_count   obj2_count 
0        04:10  obj1        1             0
1        04:10  obj1        2             0
2        04:11  obj1        3             0
3        04:12  obj2        3             1
4        04:12  obj2        3             2
5        04:12  obj1        4             2
6        04:13  obj2        4             3
</code></pre>

<p>Tried playing with cumsum but not sure that is the right way. Any suggestions?</p>
