如何在python中打印字符串拆分的第一部分

我有csv格式的数据，如：

Minneapolis-St. Paul-Bloomington MN-WI--33460 Charlotte-Gastonia-Rock Hill NC-SC--16740 Las Vegas-Paradise NV--29820 New York-White Plains-Wayne NY-NJ (MSAD)--35620

---

使用-作为字段分隔符并在拆分行后打印第一个元素

注意：组函数在python2.7 csv writer中不起作用。如果要删除的行的末尾始终有7个字符，为什么不执行行[：-7]。 i.e only : Minneapolis-St. Paul-Bloomington MN-WI Charlotte-Gastonia-Rock Hill NC-SC Las Vegas-Paradise NV & so on....

   #!/usr/bin/python
   import csv
   import re

   sample="""columnA,ColumnB,columnC
   1,Cleveland-Elyria-Mentor    OH--17460
   2,Dallas-Plano-Irving    TX  (MSAD)--19100
   3,ASJDFJKDJ-kD-JE       WA--21092"""


   open('sample.csv','w').write(sample)
   with open('sample.csv') as sample, open('final_output.csv','w') as output:
   reader = csv.reader(sample)
   writer = csv.writer(output)
   # discard input header
   next(reader)
   # write output header
   writer.writerow(['col1','col2','col3'])
   #process rows
   for row in reader:
        if row:
              for fipsplit in row[1].split('\n'):
               fipsval = re.findall(r'--(\d+)$', fipsplit)
               writer.writerow([fipsplit])
    print open('final_output.csv').read()

>>> line = " Minneapolis-St. Paul-Bloomington   MN-WI--33460"
>>> line.split("--")[0]
' Minneapolis-St. Paul-Bloomington   MN-WI'