如何根据每行字段的长度排列行？蟒蛇

Question

我有一个代码，应该打印出10行，从最短到最长的升序排序。我有一个测试文本，我想要使用位置行[4]中的字段的len来排序输出行，但我不知道该怎么做，因为我认为我需要阅读整个文本，然后按顺序在第五场的长度功能线。

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


def mapper(): 
    reader = csv.reader(sys.stdin, delimiter='\t') 
    writer = csv.writer(sys.stdout, delimiter='\t', quotechar='"', quoting=csv.QUOTE_ALL) 

    for line in reader: 
      line.sort(key=len) 
      writer.writerow(line) 



test_text = """\"\"\t\"\"\t\"\"\t\"\"\t\"333\"\t\"\" 
\"\"\t\"\"\t\"\"\t\"\"\t\"88888888\"\t\"\" 
\"\"\t\"\"\t\"\"\t\"\"\t\"1\"\t\"\" 
\"\"\t\"\"\t\"\"\t\"\"\t\"11111111111\"\t\"\" 
\"\"\t\"\"\t\"\"\t\"\"\t\"1000000000\"\t\"\" 
\"\"\t\"\"\t\"\"\t\"\"\t\"22\"\t\"\" 
\"\"\t\"\"\t\"\"\t\"\"\t\"4444\"\t\"\" 
\"\"\t\"\"\t\"\"\t\"\"\t\"666666\"\t\"\" 
\"\"\t\"\"\t\"\"\t\"\"\t\"55555\"\t\"\" 
\"\"\t\"\"\t\"\"\t\"\"\t\"999999999\"\t\"\" 
\"\"\t\"\"\t\"\"\t\"\"\t\"7777777\"\t\"\" 
""" 

# This function allows you to test the mapper with the provided test string 
def main(): 
    import StringIO 
    sys.stdin = StringIO.StringIO(test_text) 
    mapper() 
    sys.stdin = sys.__stdin__ 
main() 

我想最后的结果是：

"" "" "" "" "22" "" 
"" "" "" "" "333" "" 
"" "" "" "" "4444" "" 
"" "" "" "" "55555" "" 
"" "" "" "" "666666" "" 
"" "" "" "" "7777777" "" 
"" "" "" "" "88888888" "" 
"" "" "" "" "999999999" "" 
"" "" "" "" "1000000000" "" 
"" "" "" "" "11111111111" "" 

我怎样才能做到这一点？

Answer 1

变化排序的映射器的方法本

def mapper(): 
    reader = csv.reader(sys.stdin, delimiter='\t') 
    writer = csv.writer(sys.stdout, delimiter='\t', quotechar='"', quoting=csv.QUOTE_ALL) 

    for line in sorted(list(reader), key=lambda x: len(x[-2])): 
     writer.writerow(line)