sort pandas dataframe based on list

Question

I would like to sort the following dataframe:

Region           LSE          North      South 0                   Cn     33.330367   9.178917 1               Develd     -36.157025 -27.669988 2               Wetnds    -38.480206 -46.089908 3                Oands    -47.986764 -32.324991 4               Otherg    323.209834  28.486310 5                 Soys      34.936147   4.072872 6                  Wht     0.983977 -14.972555 

I would like to sort it so the LSE column is reordered based on the list:

lst = ['Oands','Wetnds','Develd','Cn','Soys','Otherg','Wht'] 

of, course the other columns will need to be reordered accordingly as well. Is there any way to do this in pandas?

Answer 1

The improved support for Categoricals in pandas version 0.15 allows you to do this easily:

df['LSE_cat'] = pd.Categorical(     df['LSE'],      categories=['Oands','Wetnds','Develd','Cn','Soys','Otherg','Wht'],      ordered=True ) df.sort('LSE_cat') Out[5]:     Region     LSE       North      South LSE_cat 3       3   Oands  -47.986764 -32.324991   Oands 2       2  Wetnds  -38.480206 -46.089908  Wetnds 1       1  Develd  -36.157025 -27.669988  Develd 0       0      Cn   33.330367   9.178917      Cn 5       5    Soys   34.936147   4.072872    Soys 4       4  Otherg  323.209834  28.486310  Otherg 6       6     Wht    0.983977 -14.972555     Wht 

If this is only a temporary ordering then keeping the LSE column as a Categorical may not be what you want, but if this ordering is something that you want to be able to make use of a few times in different contexts, Categoricals are a great solution.

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In later versions of pandas, sort, has been replaced with sort_values, so you would need instead:

df.sort_values('LSE_cat')