to numeric for few columns code example
Example: set select group of columns to numeric pandas
import pandas as pd
df = pd.DataFrame({'id':['a1', 'a2', 'a3', 'a4'],
'A':['0', '1', '2', '3'],
'B':['1', '1', '1', '1'],
'C':['0', '1', '1', '0']})
df[['A', 'B', 'C']] = df[['A', 'B', 'C']].apply(pd.to_numeric, axis = 1)