对数据框中的列进行排序

Question

I have a dataframe (df) with the following head() :

            BBG.XLON.BTA.S_RAWLAST  BBG.XLON.BTA.S_RAWVOLUME  \
date                                                           
2008-01-25                  256.50                  32149804   
2008-01-28                  255.25                  33574287   
2008-01-29                  258.00                  28828174   
2008-01-30                  257.25                  20637843   
2008-01-31                  259.00                  43134605   

            BBG.XLON.BTA.S_MKTCAP  BBG.XLON.BTA.S_RAWVWAP  \
date                                                        
2008-01-25             20454.2093                257.0774   
2008-01-28             20351.6907                255.3777   
2008-01-29             20570.9548                257.4734   
2008-01-30             20511.1555                257.5452   
2008-01-31             20645.2264                255.3317   

            BBG.XLON.BTA.S_RAWCLOSE  BBG.XLON.BTA.S_LAST_ADJ  \
date                                                           
2008-01-25                   256.50                   256.50   
2008-01-28                   255.25                   255.25   
2008-01-29                   258.00                   258.00   
2008-01-30                   257.25                   257.25   
2008-01-31                   259.00                   259.00   

            BBG.XLON.BTA.S_VWAP_ADJ  BBG.XLON.BTA.S_VOLUME_ADJ  \
date                                                             
2008-01-25                 257.0774                   32149804   
2008-01-28                 255.3777                   33574287   
2008-01-29                 257.4734                   28828174   
2008-01-30                 257.5452                   20637843   
2008-01-31                 255.3317                   43134605   

            BBG.XLON.BTA.S_CLOSE_ADJ  BBG.XLON.VOD.S_RAWLAST  \
date                                                           
2008-01-25                    256.50                   175.3   
2008-01-28                    255.25                   172.0   
2008-01-29                    258.00                   173.8   
2008-01-30                    257.25                   176.9   
2008-01-31                    259.00                   175.3   

              BBG.XLON.VOD.S_VWAP_ADJ_EUR  \
date                    ...                                             
2008-01-25              ...                                238.476756   
2008-01-28              ...                                231.906218   
2008-01-29              ...                                233.680915   
2008-01-30              ...                                235.735428   
2008-01-31              ...                                232.641540   

            BBG.XLON.VOD.S_CLOSE_ADJ_EUR  BBG.XLON.BTA.S_EXCHANGE_HOLIDAY  \
date                                                                        
2008-01-25                     236.77771                              NaN   
2008-01-28                     230.87560                              NaN   
2008-01-29                     234.00432                              NaN   
2008-01-30                     236.51530                              NaN   
2008-01-31                     234.46375                              NaN   

            BBG.XLON.BTA.S_CORP_ACTION  BBG.XLON.BTA.S_REPORTING  \
date                                                               
2008-01-25                         NaN                       NaN   
2008-01-28                         NaN                       NaN   
2008-01-29                         NaN                       NaN   
2008-01-30                         NaN                       NaN   
2008-01-31                         NaN                       NaN   

            BBG.XLON.BTA.S_FX  BBG.XLON.BTA.S_LAST_ADJ_EUR  \
date                                                         
2008-01-25             1.3507                   346.454550   
2008-01-28             1.3423                   342.622075   
2008-01-29             1.3464                   347.371200   
2008-01-30             1.3370                   343.943250   
2008-01-31             1.3375                   346.412500   

            BBG.XLON.BTA.S_MKTCAP_EUR  BBG.XLON.BTA.S_VWAP_ADJ_EUR  \
date                                                                 
2008-01-25               27627.500502                   347.234444   
2008-01-28               27318.074427                   342.793487   
2008-01-29               27696.733543                   346.662186   
2008-01-30               27423.414904                   344.337932   
2008-01-31               27612.990310                   341.506149   

            BBG.XLON.BTA.S_CLOSE_ADJ_EUR  
date                                      
2008-01-25                    346.454550  
2008-01-28                    342.622075  
2008-01-29                    347.371200  
2008-01-30                    343.943250  
2008-01-31                    346.412500  

I am trying to sort the columns so that they are sorted by there column name alphabetically. (so in this example all the BBG.XLON.BTA* are before BBG.XLON.VOD* . I am however am having a problem.

I have tried:

df.sort_index(axis=1)

df[sorted(df.columns)]

and

df.reindex_axis(sorted(df.columns), axis=1)

but cannot get the columns to reorder. How can I achieve this?

Answer 1

Per Stefan and Yakym Pirozhenko

df = df.sort_index(axis=1)

or

df.sort_index(axis=1, inplace=1)

Doing df.sort_index(axis=1) just returns a dataframe sorted how you want but does nothing with it unless you either assign it to df or pass the inplace=True parameter.

Also could have:

df = df.T.sort_index().T

What you are asking is a very well established task with a very well established solution. This is why you have 3 people and probably more in a few minutes telling you the same thing. If it isn't working, then it's probably due to something else you are doing that you haven't told us. The best thing to do is provide a complete representation of what you are doing.

See MCVE for more guidance.