How to convert index of a pandas dataframe into a column

Question

This seems rather obvious  but I can t seem to figure out how to convert an index of data frame to a column   For example   df          gi       ptt loc  0  384444683      593    1  384444684      594   2  384444686      596     To   df      index1    gi       ptt loc  0  0     384444683      593    1  1     384444684      594   2  2     384444686      596

User · Accepted Answer

either   df  index1     df index   or   reset index   df reset index level 0  inplace True      so  if you have a multi-index frame with 3 levels of index  like    gt  gt  gt  df                        val tick       tag obs         2016-02-26 C   2    0 0139 2016-02-27 A   2    0 5577 2016-02-28 C   6    0 0303   and you want to convert the 1st  tick  and 3rd  obs  levels in the index into columns  you would do    gt  gt  gt  df reset index level   tick    obs              tick  obs     val tag                         C   2016-02-26    2  0 0139 A   2016-02-27    2  0 5577 C   2016-02-28    6  0 0303

User · Answer

A very simple way of doing this is to use reset index   method For a data frame df use the code below   df reset index inplace True    This way  the index will become a column  and by using inplace as True this become permanent change

User · Answer

rename axis   reset index  You can first rename your index to a desired label  then elevate to a series   df   df rename axis  index1   reset index    print df      index1         gi  ptt loc 0       0  384444683      593 1       1  384444684      594 2       2  384444686      596   This works also for MultiIndex dataframes   print df                           val   tick       tag obs           2016-02-26 C   2    0 0139   2016-02-27 A   2    0 5577   2016-02-28 C   6    0 0303  df   df rename axis   index1    index2    index3    reset index    print df          index1 index2  index3     val 0  2016-02-26      C       2  0 0139 1  2016-02-27      A       2  0 5577 2  2016-02-28      C       6  0 0303

User · Answer

To provide a bit more clarity  let s look at a DataFrame with two levels in its index  a MultiIndex    index   pd MultiIndex from product    TX    FL    CA                                           North    South                                         names   State    Direction     df   pd DataFrame index index                     data np random randint 0  10   6 4                       columns list  abcd        The reset index method  called with the default parameters  converts all index levels to columns and uses a simple RangeIndex as new index   df reset index       Use the level parameter to control which index levels are converted into columns  If possible  use the level name  which is more explicit  If there are no level names  you can refer to each level by its integer location  which begin at 0 from the outside  You can use a scalar value here or a list of all the indexes you would like to reset   df reset index level  State     same as df reset index level 0      In the rare event that you want to preserve the index and turn the index into a column  you can do the following     for a single level df assign State df index get level values  State       for all levels df assign   df index to frame

User · Answer

df1   pd DataFrame   gi   232 66 34 43   ptt   342 56 662 123    p   df1 index values df1 insert  0  column  new  value   p  df1      new     gi     ptt 0    0      232    342 1    1      66     56  2    2      34     662 3    3      43     123

User · Answer

For MultiIndex you can extract its subindex using   df  si name     R index get level values  si name      where si name is the name of the subindex

User · Answer

If you want to use the reset index method and also preserve your existing index you should use   df reset index   set index  index   drop False    or to change it in place   df reset index inplace True  df set index  index   drop False  inplace True    For example   print df            gi  ptt loc 0  384444683      593 4  384444684      594 9  384444686      596  print df reset index       index         gi  ptt loc 0      0  384444683      593 1      4  384444684      594 2      9  384444686      596  print df reset index   set index  index   drop False          index         gi  ptt loc index 0          0  384444683      593 4          4  384444684      594 9          9  384444686      596   And if you want to get rid of the index label you can do   df2   df reset index   set index  index   drop False  df2 index name   None print df2     index         gi  ptt loc 0      0  384444683      593 4      4  384444684      594 9      9  384444686      596

[python] How to convert index of a pandas dataframe into a column?

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