这本书的4.3.4节数据转化，设置哑变量
不懂是哪里代码敲错了
import pandas as pd
df_industry=DataAPI.EquIndustryGet(secID=u"",ticker=u"000001,600001",industryVersionCD=u"010303",industry=u"",industryID=u"",industryID1=u"",industryID2=u"",industryID3=u"",intoDate=u"20180101",field=u"secID,industryName1",pandas="1")
industry_list=df_industry['industryName1'].drop_duplicates().tolist()

def get(x):
    ind_s=pd.Series([0]*len(industry_list),index=industry_list)# Series是一个一维的数据结构,用list, index构建Series
    if len(df_industry[df_industry['secID']==x])>0:
        ind=df_industry[df_industry['secID']==x]['industryName1'].value[0]
        ind_s.loc[ind]=1
    #print ind_s
    return ind_s

df_[industry_list]=df_['secID'].apply(lambda x: get(x))
df_head()


提示NameError                                 Traceback (most recent call last)
<mercury-input-8-BE404B509ABF440F82C31EAC8FA23539> in <module>()     11     return ind_s     12 ---> 13 df_[industry_list=df_['secID'.apply(lambda x: get(x))     14 df_head()     15 NameError: name 'df_' is not defined

应该怎么改正呢？求助论坛高手！