How to add new column to an dataframe to the front not end

Question

How to add a new variable to an existing data frame  but I want to add to the front not end  eg  my dataframe is  b c d 1 2 3 1 2 3 1 2 3   I want to add a new variable a  so the dataframe will looks like  a b c d 0 1 2 3 0 1 2 3 0 1 2 3

User · Answer

cbind inherents order by its argument order.

User your first column(s) as your first argument

cbind(fst_col , df)

  fst_col   df_col1   df_col2
1 0             0.2      -0.1
2 0             0.2      -0.1
3 0             0.2      -0.1
4 0             0.2      -0.1
5 0             0.2      -0.1

cbind(df, last_col)

  df_col1   df_col2  last_col
1 0.2      -0.1             0
2 0.2      -0.1             0
3 0.2      -0.1             0
4 0.2      -0.1             0
5 0.2      -0.1             0

User · Answer

Add column  a     gt  df  a    lt - 0  gt  df   b c d a 1 1 2 3 0 2 1 2 3 0 3 1 2 3 0      Sort by column using colum name    gt  df  lt - df c  a    b    c    d     gt  df   a b c d 1 0 1 2 3 2 0 1 2 3 3 0 1 2 3      Or sort by column using index    gt  df  lt - df colnames df  c 4 1 3     gt  df   a b c d 1 0 1 2 3 2 0 1 2 3 3 0 1 2 3

User · Answer

If you want to do it in a tidyverse manner  try add column from tibble  which allows you to specifiy where to place the new column with  before or  after parameter   library tibble   df  lt - data frame b   c 1  1  1   c   c 2  2  2   d   c 3  3  3   add column df  a   0   before   1       a b c d   1 0 1 2 3   2 0 1 2 3   3 0 1 2 3

User · Answer

The previous answers show 3 approaches   By creating a new data frame By using  cbind  By adding column  a   and sort data frame by columns using column names or indexes   Let me show  4 approach  By using  cbind  and  rename  that works for my case  1  Create data frame  df  lt - data frame b   c 1  1  1   c   c 2  2  2   d   c 3  3  3    2  Get values for  new  column  new column   c 0  0  0   3  Combine  new  column with existed  df  lt - cbind new column  df   4  Rename  new  column name  colnames df  1   lt -  a

User · Answer

Use cbind e g   df  lt - data frame b   runif 6   c   rnorm 6   cbind a   0  df    giving    gt  cbind a   0  df    a         b          c 1 0 0 5437436 -0 1374967 2 0 0 5634469 -1 0777253 3 0 0 9018029 -0 8749269 4 0 0 1649184 -0 4720979 5 0 0 6992595  0 6219001 6 0 0 6907937 -1 7416569

User · Answer

df  lt - data frame b   c 1  1  1   c   c 2  2  2   d   c 3  3  3   df      b c d    1 1 2 3    2 1 2 3    3 1 2 3  df  lt - data frame a   c 0  0  0   df  df      a b c d    1 0 1 2 3    2 0 1 2 3    3 0 1 2 3

[r] How to add new column to an dataframe (to the front not end)?

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