How to change an element of a list

Question

I assign the column index of a dataframe to an object.

Object1 = df.columns

Next, I try to change the 2nd element of this list.

Object1[1]='Fred'

I am getting the following error when I attempt to change the element of a list.

'TypeError: Index does not support mutable operations'

I simply expect the second element (column) name to be "Fred".

not sure I get it right, are you trying to change the name of the column? are you using pandas? — adhg, Jun 05 '19 at 19:55
The values *in* the dataframe are mutable, but the indices and column names are not. To change column names, you'll have to add a new column with that name and drop the old one — C.Nivs, Jun 05 '19 at 19:55
I'm trying to change the name of a column. The actual code is a for loop, where I am trying to rename a particular column each type the loop executes. I get the same error so I showed the simple example. — WON_Eric, Jun 05 '19 at 19:59

score 4 · Answer 1 · edited Jun 05 '19 at 20:05

4

The answer to your question. Columns are an index, and they are immutable. You can, however do something like this:

test = df.columns.values
test[1] = 'Fred'
df.columns = test

Or use the dedicated method pandas.DataFrame.rename() like this:

df.rename(columns={df.columns[1]: "Fred"}, inplace=True)

edited Jun 05 '19 at 20:05

FabienP

answered Jun 05 '19 at 19:57

krflol

score 0 · Accepted Answer · answered Jun 05 '19 at 19:59

0

Try the following:

Object1 = df.columns.values
Object1[1]='Fred'

answered Jun 05 '19 at 19:59

M. Shen

2 Answers2