Вы можете попробовать это:
df['statute'] = [re.split(r'[^a-zA-Z]+', val.strip()) for val in df['statutInit']]
df['statute'] = [' '.join(val) for val in df['statute']]
df['taux'] = [re.split(r'[a-zA-Z:\s]+', val.strip()) for val in df['statutInit']]
df['taux'] = [''.join(val) for val in df['taux']]
print(df)
Вывод:
statutInit statute taux
0 Majoration : 0,06‰ Capital Majoration Capital 0,06‰