如何从大csv文件中仅获取一列？

Question

cat csv文件

 1,10000e,0,a18b8200,3,4,1,1d,0,3,2,0,0,ffff,3d3e68143f8d65f8c3284d00c2e52800,ffff,3d79bab5406dfdebc41
      2 1,100022,0,8c5de9a0,0,4,1,1d,0,3,2,0,0,ffff,10b30b00000000000010a3040001b380
      3 1,10007,0,8ed525c0,3,4,1,1f,0,3,2,0,0,7777,00ffffff00ffffff00ffffff00ffffff,7777,00ffffff00ffffff00ff
      4 1,1000bd,0,a18bb880,3,4,1,1f,0,3,2,0,0,ffff,3d21853a3f3b9bb2c2a98200421f9400,ffff,3d2188d53f3f08acc2a
      5 1,1000e0,0,a18b9940,3,4,1,1e,0,3,2,0,0,ffff,3d298fa83fedc6c4c3801980c2d93600,ffff,3d2b3fa73ff191e3c38
      6 1,10011,0,8ed32840,3,4,1,1a,0,3,2,0,0,7777,00ffffff00ffffff00ffffff00ffffff,7777,00ffffff00ffffff00ff
      7 1,100137,0,8c406000,3,4,1,1f,0,3,2,0,0,7777,00ffffff00ffffff00ffffff00ffffff,7777,00ffffff00ffffff00f
....

在python代码中

 def csv_slice(csvinfile, csvoutfile, ncol):
     reader = csv.reader(open(csvinfile, 'rb'), delimiter=',')
     writer = csv.writer(open(csvoutfile, 'wb'), delimiter=',')
     for row in reader:
         writer.writerow(row[ncol]) # result : a char
         print row[ncol]

我是python的新手。怎样才能得到一个只在列上的正确值？ 上面的代码只能使逗号分隔字符，如 通缉令：10000e 但是，结果：每行1,0,0,0，e

提前谢谢

Answer 1

试试看

writer.writerow([row[ncol]]) # result : a char

writerow()方法需要一个序列作为其参数。当您传递一个字符串时，它会假定字符串的每个字符都是该行的一个元素。建议的更改将所需的值转换为包含单个字符串元素的列表。你知道吗