初学python条件判断出错，请老手、高手、大神随手拯救

Question

背景：初学python，计划从表格苦海脱身

import pandas as pd
df = pd.read_csv(r'D:\Desktop\202103fcx_payee.csv',names=['no_num','xingming','mobile','mbl_bz','accounttype','accountno','idtype','idno','idno_bz','operatorcode','operator','mkcom','date','no_use'],header=None)
ct = len(df["idno"])
m = 0
print(len(df["idno"][m])!=18)
while m < ct :
    if len(df["idno"][m])!=18 :
        df["idno_bz"][m]="no_gf"
        m = m+1
    else :
        df["idno_bz"][m]="gf"
        m = m+1

运行后提示if len(df["idno"][m])!=18 :这一行出错，一堆错误代码看不懂，但用print（len(df["idno"][m])）没有问题

请老手、高手、大神随手拯救

错误提示如下：

 

Answer 1

不需要那么复杂，一句就行。df['idno_bz'] = df['idno'].map(lambda x: 'gf' if x==18 else 'no_gf' )