Python 使用if-elif语句向数据帧添加空值

我尝试了以下网站，以寻求失败的答案：

我需要通过python函数添加空值

from numpy import nan

def f(row):
    if row['model'] == 'C5' and row['x'] <= 600:
        val = 600
    elif row['model'] == 'C5' and row['x'] > 600 and row['score'] <= 675:
        val = 675
    elif row['model'] == 'C5' and row['x'] > 675 and row['score'] <= 710:
        val = 710
    elif row['model'] == 'C5' and row['x'] > 710 and row['score'] <= 745:
        val = 745 
    elif row['CREDIT_MODEL_CODE'] == 'C5' and row['x'] > 745:
        val = 999
    elif row['model'] == 'C5' and row['x'] == 'X': 
        val = 3
    elif row['model'] == 'C5' and row['x'] == 'T': 
        val = 2
    elif row['model'] == "":
        val = 1
    return val

df['column'] = df.apply(f, axis = 1)

--->50 val==“” 51 52返回值

UnboundLocalError:（“之前引用了局部变量'val' 赋值“，”发生在索引60'）

---

看看pd.cut~为什么不干脆

else:

Hi@MaartenFabré。这仍然会抛出一个错误，因为它期望

val

有一个值。请看pd.cut~为什么不干脆

else:

Hi@martenfabré。这仍然会抛出一个错误，因为它希望

val

有一个值。

 48 
 49     else: