In [17]:
cohorts[cohorts['FirstOrder']=='2009-02']
Out[17]:
FirstOrder OrderPeriod TotalUsers
15 2009-02 2009-02 15
16 2009-02 2009-03 3
17 2009-02 2009-04 5
18 2009-02 2009-05 1
19 2009-02 2009-06 4
20 2009-02 2009-07 4
21 2009-02 2009-08 4
22 2009-02 2009-09 5
23 2009-02 2009-10 5
24 2009-02 2009-11 4
25 2009-02 2009-12 3
26 2009-02 2010-01 3
27 2009-02 2010-02 5