pydata/pandas — pull request #8372 by jreback (2014-09-23 18:02:55+00:00)
Title: BUG: bug in non-evently divisible offsets when resampling (e.g. '7s') (GH8317)

closes #8317

```
In [1]: data = """date,time,value
...: 11-08-2014,00:00:01.093,1
...: 11-08-2014,00:00:02.159,1
...: 11-08-2014,00:00:02.667,1
...: 11-08-2014,00:00:03.175,1
...: 11-08-2014,00:00:07.058,1
...: 11-08-2014,00:00:07.362,1
...: 11-08-2014,00:00:08.324,1
...: 11-08-2014,00:00:08.830,1
...: 11-08-2014,00:00:08.982,1
...: 11-08-2014,00:00:09.815,1
...: 11-08-2014,00:00:10.540,1
...: 11-08-2014,00:00:11.061,1
...: 11-08-2014,00:00:11.617,1
...: 11-08-2014,00:00:13.607,1
...: 11-08-2014,00:00:14.535,1
...: 11-08-2014,00:00:15.525,1
...: 11-08-2014,00:00:17.960,1
...: 11-08-2014,00:00:20.674,1
...: 11-08-2014,00:00:21.191,1"""

In [2]: df = pd.read_csv(StringIO(data), parse_dates={'timestamp': ['date', 'time']}, index_col='timestamp')

In [3]: df
Out[3]:
value
timestamp
2014-11-08 00:00:01.093000 1
2014-11-08 00:00:02.159000 1
2014-11-08 00:00:02.667000 1
2014-11-08 00:00:03.175000 1
2014-11-08 00:00:07.058000 1
2014-11-08 00:00:07.362000 1
2014-11-08 00:00:08.324000 1
2014-11-08 00:00:08.830000 1
2014-11-08 00:00:08.982000 1
2014-11-08 00:00:09.815000 1
2014-11-08 00:00:10.540000 1
2014-11-08 00:00:11.061000 1
2014-11-08 00:00:11.617000 1
2014-11-08 00:00:13.607000 1
2014-11-08 00:00:14.535000 1
2014-11-08 00:00:15.525000 1
2014-11-08 00:00:17.960000 1
2014-11-08 00:00:20.674000 1
2014-11-08 00:00:21.191000 1

In [4]: df.resample('6s', how='sum')
Out[4]:
value
timestamp
2014-11-08 00:00:00 4
2014-11-08 00:00:06 9
2014-11-08 00:00:12 4
2014-11-08 00:00:18 2
In [5]: df.resample('7s', how='sum')
Out[5]:
value
timestamp
2014-11-08 00:00:00 4
2014-11-08 00:00:07 10
2014-11-08 00:00:14 4
2014-11-08 00:00:21 1

In [6]: df.resample('11s', how='sum')
Out[6]:
value
timestamp
2014-11-08 00:00:00 11
2014-11-08 00:00:11 8

In [7]: df.resample('13s', how='sum')
Out[7]:
value
timestamp
2014-11-08 00:00:00 13
2014-11-08 00:00:13 6

In [8]: df.resample('17s', how='sum')
Out[8]:
value
timestamp
2014-11-08 00:00:00 16
2014-11-08 00:00:17 3
```