Issue with 'arrange' when df has an index about dfply

[kieferk]

Good catch! This is in fact a bug. It was happening because I was using the original dataframe's index to sort, then re-indexing with the sorted indices. When there were duplicate indices it would duplicate the rows.

Should be fixed now. I just changed to indexing using .iloc instead.

I tried the same on my machine with the new master branch:

from dfply import *
utime = pd.DataFrame({"u":1,"eventTime":["01-01-1971 01:04:00","01-01-1971 02:07:00","01-01-1971 01:09:00","01-01-1971 01:10:00"]})

print(utime >> arrange(X.eventTime))
             eventTime  u
0  01-01-1971 01:04:00  1
2  01-01-1971 01:09:00  1
3  01-01-1971 01:10:00  1
1  01-01-1971 02:07:00  1

utime = utime.set_index("u")

print(utime >> arrange(X.eventTime))
             eventTime
u                     
1  01-01-1971 01:04:00
1  01-01-1971 01:09:00
1  01-01-1971 01:10:00
1  01-01-1971 02:07:00

Which is the behavior you expected. If you pull the master branch and reinstall it should work.