如何解析Python字符串中的一个字符[[副本]

我有一个数据帧,想把第9个字符解析成第二列。不过,我还是漏掉了语法。

#develop the data
df = pd.DataFrame(columns = ["vin"], data = ['LHJLC79U58B001633','SZC84294845693987','LFGTCKPA665700387','L8YTCKPV49Y010001',
                                             'LJ4TCBPV27Y010217','LFGTCKPM481006270','LFGTCKPM581004253','LTBPN8J00DC003107',
                                             '1A9LPEER3FC596536','1A9LREAR5FC596814','1A9LKEER2GC596611','1A9L0EAH9C596099',
                                             '22A000018'])

df['manufacturer'] = ['A','A','A','A','B','B','B','B','B','C','C','D','D']

def check_digit(df):
    df['check_digit'] = df['vin'][8]
    print(df['checkdigit'])]

出于某种原因,这会将第8行VIN放在每行中。