Divide multiple columns by another column in pandas

Question

I need to divide all but the first columns in a DataFrame by the first column.

Here's what I'm doing, but I wonder if this isn't the "right" pandas way:

df = pd.DataFrame(np.random.rand(10,3), columns=list('ABC'))  df[['B', 'C']] = (df.T.iloc[1:] / df.T.iloc[0]).T 

Is there a way to do something like df[['B','C']] / df['A']? (That just gives a 10x12 dataframe of nan.)

Also, after reading some similar questions on SO, I tried df['A'].div(df[['B', 'C']]) but that gives a broadcast error.

Answer 1

I believe df[['B','C']].div(df.A, axis=0) and df.iloc[:,1:].div(df.A, axis=0) work.

Answer 2

do: df.iloc[:,1:] = df.iloc[:,1:].div(df.A, axis=0) 

This will divide all columns other than the 1st column with the 'A' column used as divisor.

Results are 1st column + all columns after / 'divisor column'.