将某一列数据进行拆分
new_id, new_code = list(), list()
for i in range(df.shape[0]):
a_id = df['loan_id'][i]
r_code = df['irr24_reason_codes'][i]
code_list = r_code.split(',')
for j in range(len(code_list)):
new_id.append(a_id)
new_code.append(code_list[j])
data_irr24_reason_code = pd.DataFrame({'loan_id': new_id, 'irr24_reason_code': new_code})