i have a dataframe like this:
我有这样的数据帧:
mcnfecha mcnnumedoc mcncuenta
0 2015-12-31 1.0 14353605
96 2015-12-31 7.0 15400505
97 2015-12-31 7.0 15920505
98 2015-12-31 7.0 41351005
99 2015-12-31 7.0 41352150
100 2015-12-31 7.0 41352151
101 2015-12-31 7.0 15922005
95 2015-12-31 7.0 15281005
102 2015-12-31 7.0 15922010
104 2015-12-31 7.0 21050505
105 2015-12-31 7.0 21051004
106 2015-12-31 7.0 21051007
107 2015-12-31 7.0 21051008
