Question

这是我的代码我的目标是从大文本文件中打印一个特定的整行，其中字符串等于＆＃34; SAMPLE TYPE＆＃34;当我尝试在对象中打印如何从整个文件打印指定的行

import re
target = open("debug.txt", "r")
for line in target:
    search=re.search("[SAMPLE TYPE]",line)
    v1=search
    print v1

输出：

None
None
None
None
None
<_sre.SRE_Match object at 0x7f870b7d5578>in this place instead of this i need to print the specifed line and i dont want the lines which doesnt contain specifed string.

我的输入文件数据：

HLS| 04/14/16 17:56:58:933 |hls_tsr_module.cpp|ReceiveData              |418 |DEBUG: Data copied to TSD from TSR is 0
HLS| 04/14/16 17:56:58:933 |mpm_h264.cpp   |FrameType                |1341|DEBUG: AU_DELIM NALU Unit Type
HLS| 04/14/16 17:56:58:933 |mpm_h264.cpp   |FrameType                |1341|DEBUG: SEI NALU Unit Type
HLS| 04/14/16 17:56:58:933 |mpm_h264.cpp   |FrameType                |1341|DEBUG: NON_IDR_PICTURE NALU Unit Type
HLS| 04/14/16 17:56:58:933 |mpm_h264.cpp   |FrameType                |1377|DEBUG: B Frame Received
HLS| 04/14/16 17:56:58:933 |hls_tsd_module.cpp|ProcessVideoBuffer       |4151|DEBUG: SAMPLE TYPE: B - FRAME PTS: 8573002542 DTS: 8573002542 
HLS| 04/14/16 17:56:58:933 |hls_tsd_module.cpp|ProcessVideoBuffer       |4193|DEBUG: Video send pts 8573002542
HLS| 04/14/16 17:56:58:933 |hls_tsm_module.cpp|AlternateFrameInterLeave |11770|DEBUG: Audio Record Status is 1
HLS| 04/14/16 17:56:58:934 |hls_tsd_module.cpp|ProcessVideoBuffer       |4261|DEBUG: Frame video pts 8573004043
HLS| 04/14/16 17:56:58:934 |hls_tsm_module.cpp|AlternateFrameInterLeave |11770|DEBUG: Audio Record Status is 1
HLS| 04/14/16 17:56:58:934 |hls_tsd_module.cpp|SegmentStream            |1597|DEBUG: Not an AV/Subtitle Packet 256
HLS| 04/14/16 17:56:58:934 |mpm_h264.cpp   |FrameType                |1341|DEBUG: AU_DELIM NALU Unit Type
HLS| 04/14/16 17:56:58:934 |mpm_h264.cpp   |FrameType                |1341|DEBUG: SEI NALU Unit Type
HLS| 04/14/16 17:56:58:934 |mpm_h264.cpp   |FrameType                |1341|DEBUG: NON_IDR_PICTURE NALU Unit Type
HLS| 04/14/16 17:56:58:934 |mpm_h264.cpp   |FrameType                |1377|DEBUG: B Frame Received
HLS| 04/14/16 17:56:58:934 |hls_tsd_module.cpp|ProcessVideoBuffer       |4151|DEBUG: SAMPLE TYPE: B - FRAME PTS: 8573004043 DTS: 8573004043

Answer 1

import os
os.system('grep -rnw "[FOLDER_NAME]" -e "SEARCH_STRING" > OP.txt')

Answer 2

Python regex search方法返回匹配对象或None（如果没有找到）。要从匹配对象中获取字符串，您需要调用.group()。

In [1]: import re

In [2]: re.search("a", "aaa")
Out[2]: <_sre.SRE_Match at 0x7fe3514e98b8>

In [3]: re.search("a", "aaa").group()
Out[3]: 'a'

查看the docs和this或this SO问题。

Answer 3

这是如何做到的：

with open("debug.txt", "r") as target:
    for line in target:
        if "[SAMPLE TYPE]" in line:
            print(line)

请注意，我使用上下文管理器（with语句）来打开文件。此外，如果您只是想在另一个字符串中找到子字符串，则不需要re。

Answer 4

尝试：

if search:
    print(line)

正在返回的正则表达式对象在无法找到任何内容时将计算为False。

Answer 5

从documentation：re.search返回MatchObject个实例。该文档向您展示了如何访问搜索到的字符串，例如v1.group(0)。

如何从文件中打印特定行，它与大文本文件中的输入字符串匹配？

5 个答案: