如何从大的csv文件中只获取一列？

Question

猫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

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] 

我在Python中的新手。我怎样才能得到一个适当的价值，只有在列上？ 上面的代码不仅可以使逗号分隔的性格，像 想：10000e 但是，结果是：1,0,0,0,0，每e行

感谢，提前

Answer 1

尝试

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

writerow()方法需要一个序列作为其参数。当你向它传递一个字符串时，它确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具有单个字符串元素的列表。