copy columns without header name

[issac_n]

how to copy columns from df to new columns without knowing the columns header name?

eg below is with the known header name
df["new"]= df["old"]
how about without known the header name?
df["new"] = df[0] this does not work

[glidecode]

You should be able to refer to the dataframes column by its index position as:

df.columns[1]

Assuming that the 'old' column is at position 1

Thus I think you can go:

df['new'] = df.columns[1]