使用head -n从测试结果中检索前几行
使用head -n从测试结果中检索前几行
提问于 2019-03-21 02:20:56
我正在测试python程序，并希望检索它的前两行结果。
$ python twoSum.py
DEBUG-MainProcess:31921-MainThread:140190102726464 find: 151
DEBUG-MainProcess:31921-MainThread:140190102726464 j: None
DEBUG-MainProcess:31921-MainThread:140190102726464 find: 194
DEBUG-MainProcess:31921-MainThread:140190102726464 j: None
DEBUG-MainProcess:31921-MainThread:140190102726464 find: 247
DEBUG-MainProcess:31921-MainThread:140190102726464 j: None
DEBUG-MainProcess:31921-MainThread:140190102726464 find: 192
DEBUG-MainProcess:31921-MainThread:140190102726464 j: None
DEBUG-MainProcess:31921-MainThread:140190102726464 find: 206
DEBUG-MainProcess:31921-MainThread:140190102726464 j: None
DEBUG-MainProcess:31921-MainThread:140190102726464 find: 171
DEBUG-MainProcess:31921-MainThread:140190102726464 j: None
DEBUG-MainProcess:31921-MainThread:140190102726464 find: 170
DEBUG-MainProcess:31921-MainThread:140190102726464 j: None
DEBUG-MainProcess:31921-MainThread:140190102726464 find: 190
DEBUG-MainProcess:31921-MainThread:140190102726464 j: None
DEBUG-MainProcess:31921-MainThread:140190102726464 find: 132
DEBUG-MainProcess:31921-MainThread:140190102726464 j: 63
[8, 63]
.
----------------------------------------------------------------------
Ran 1 test in 0.001s
OK使用head来处理文本
$ python twoSum.py | head -n 1
DEBUG-MainProcess:31978-MainThread:140699277834048 find: 259
DEBUG-MainProcess:31978-MainThread:140699277834048 j: None
DEBUG-MainProcess:31978-MainThread:140699277834048 find: 235
DEBUG-MainProcess:31978-MainThread:140699277834048 j: None
DEBUG-MainProcess:31978-MainThread:140699277834048 find: 133
DEBUG-MainProcess:31978-MainThread:140699277834048 j: None
DEBUG-MainProcess:31978-MainThread:140699277834048 find: 274
DEBUG-MainProcess:31978-MainThread:140699277834048 j: None
DEBUG-MainProcess:31978-MainThread:140699277834048 find: 265
DEBUG-MainProcess:31978-MainThread:140699277834048 j: None
DEBUG-MainProcess:31978-MainThread:140699277834048 find: 257
DEBUG-MainProcess:31978-MainThread:140699277834048 j: None
DEBUG-MainProcess:31978-MainThread:140699277834048 find: 280
DEBUG-MainProcess:31978-MainThread:140699277834048 j: None
DEBUG-MainProcess:31978-MainThread:140699277834048 find: 134
DEBUG-MainProcess:31978-MainThread:140699277834048 j: None
DEBUG-MainProcess:31978-MainThread:140699277834048 find: 138
DEBUG-MainProcess:31978-MainThread:140699277834048 j: None
DEBUG-MainProcess:31978-MainThread:140699277834048 find: 145
DEBUG-MainProcess:31978-MainThread:140699277834048 j: 75
.
----------------------------------------------------------------------
Ran 1 test in 0.001s它不起作用，我如何才能收回我想要看到的前几行。
回答 1
Ask Ubuntu用户
回答已采纳
发布于 2019-03-21 02:40:51
可能DEBUG-输出将转到标准错误流，而不是标准输出流--尝试
python twoSum.py 2>&1 | head -n 1 将stderr (文件描述符#2)重定向到stdout (文件描述符#1)；或(bash速记)
python twoSum.py |& head -n 1有关更多信息，请参见相关问题用带管道和符号的grep过滤查找中的错误。
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原文链接：
https://askubuntu.com/questions/1127410
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