python - Keeping columns in the specified order when using UseCols in Pandas Read_CSV

Question

I have a csv file with 50 columns of data. I am using Pandas read_csv function to pull in a subset of these columns, using the usecols parameter to choose the ones I want:

cols_to_use = [0,1,5,16,8]
df_ret = pd.read_csv(filepath, index_col=False, usecols=cols_to_use)

The trouble is df_ret contains the correct columns, but not in the order I specified. They are in ascending order, so [0,1,5,8,16]. (By the way the column numbers can change from run to run, this is just an example.) This is a problem because the rest of the code has arrays which are in the "correct" order and I would rather not have to reorder all of them.

Is there any clever pandas way of pulling in the columns in the order specified? Any help would be much appreciated!

Answer 1

you can reuse the same cols_to_use list for selecting columns in desired order:

df_ret = pd.read_csv(filepath, index_col=False, usecols=cols_to_use)[cols_to_use]