Python运行报expected indented block无效语法错误求排查

触发expected indented block - invalid syntax错误的直接原因是多行条件判断的续行缩进不规范，破坏了Python的代码块层级识别规则。
你代码中两处三层嵌套if的多行条件都用了反斜杠\续行，但续行后的and语句缩进比if声明行少了4个空格，导致解释器判定最内层if语句在第一行末尾就已经结束，冒号后没有跟随对应缩进的执行块，直接抛出语法错误。报错定位到qr_os = qr_os.append(qr2.iloc[i],ignore_index=True)行，是因为解释器扫到这行时才发现块结构不匹配。

• 弃用容易出错的反斜杠续行写法，改用圆括号包裹多行判断条件，不需要额外加反斜杠，缩进容错性更高
• 统一嵌套代码的缩进规则：每一层嵌套比上一层多缩进4个空格，if/for/while等语句的冒号后，执行代码必须比声明行多一层缩进
• 补充提示：pandas 2.0+版本已经正式删除DataFrame.append()API，长期运行建议替换为pd.concat()实现行拼接，避免版本兼容问题

d = qr2.iloc[0].to_dict()
for i in list(d.keys()):
    d[i] = np.nan


for i in range(len(qr2)):
    if qr2.iloc[i]['PrimaryRiskId'] not in list(aID):
        if qr2.iloc[i]['LinkageLinkType'] != 'B2B_COUNTER_TRADE':
            if (qr2.iloc[i]['CreatedBy'] != 'koala_manual'
                and qr2.iloc[i]['Book'] not in {'PIZH','SIBZ','IIBZ','OTCL','FXNG'}
                and qr2.iloc[i]['SubCategoryValuation'] not in {'EQCertificate','EQCertificatePlus','EQCappucino','EQCliquetUnlimitedDownside'}):
                qr_rec = qr_rec.append(qr2.iloc[i], ignore_index=True)
             
d[list(d.keys())[0]] = 'records which are in cleaned QueryResults and are not in TMRActivity'
qr_rec = qr_rec.append(d, ignore_index=True)


#### QueryResults exceptions which are out of scope###

qr_os = qr2.iloc[[0,1]]

for i in range(len(qr2)):
    if qr2.iloc[i]['PrimaryRiskId'] not in list(aID):
        if qr2.iloc[i]['LinkageLinkType'] == 'B2B_COUNTER_TRADE':
            if (qr2.iloc[i]['CreatedBy'] == 'koala_manual'
                and qr2.iloc[i]['Book'] in {'PIZH','SIBZ','IIBZ','OTCL','FXNG'}
                and qr2.iloc[i]['SubCategoryValuation'] in {'EQCertificate','EQCertificatePlus','EQCappucino','EQCliquetUnlimitedDownside'}):
                qr_os = qr_os.append(qr2.iloc[i], ignore_index=True)
            
d[list(d.keys())[0]] = 'records which are in cleaned QueryResults and are not in TMRActivity and should be treated as o/s'
qr_os = qr_os.append(d, ignore_index=True)

内容的提问来源于stack exchange，提问作者Paula Ciesielska