pandas, multiply all the numeric values in the data frame by a constant

Question

How to multiply all the numeric values in the data frame by a constant without having to specify column names explicitly? Example:

In [13]: df = pd.DataFrame         


        

Answer 1

The other answer specifies how to multiply only numeric columns. Here's how to update it:

df = pd.DataFrame({'col1': ['A','B','C'], 'col2':[1,2,3], 'col3': [30, 10,20]})

s = df.select_dtypes(include=[np.number])*3

df[s.columns] = s

print (df)

  col1  col2  col3
0    A     3    90
1    B     6    30
2    C     9    60