Question

我有一个代码应该打印出从最短到最长的升序排序的10行。我有一个测试文本，我想使用位置线[4]中的字段len来排序输出行，但我不知道怎么做，因为我认为我需要阅读整个文本并在订购之后在第5场的长度函数中的线。

#!/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()

我希望最终结果是：

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

我该怎么做？

Answer 1

将映射器方法更改为此

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)

如何通过每行字段的len对行进行排序？蟒蛇

1 个答案: