如何找到一个文本文件中的行子串并打印特定行

Question

我有一个这样的文件：

[739:246050] START of MACThread:receved msg type[47] 
[739:247021] PHYThrad: DSPMsgQ Received: msg type is[130] and SFNSF [14997] [SFN:937 SF:5] 
[739:247059] START of MACThread:receved msg type[47] 

我需要打印包含“START”使用python行...

Answer 1

with open("file.txt") as f: 
    lines=f.readlines() 
    for i in lines: 
     if i.__contains__("START"): 
      print i 

假设你有一个包含数据的file.txt的 你可以使用下面的代码 Happing编码

Answer 2

如从命令行一个衬里：

代码：

python -c "import sys;[sys.stdout.write(l) for l in sys.stdin if ' START ' in l]" < file1 

个

结果：

[739:246050] START of MACThread:receved msg type[47] 
[739:247059] START of MACThread:receved msg type[47] 

Answer 3

使用条件表达式'START' in line其中line是要检查线路。

Answer 4

您可以使用re。

查看演示。

https://regex101.com/r/sLKG1U/3

import re 

regex = r"^\[[^\]]*\]\s*(START\b.*)" 

test_str = ("[739:246050] START of MACThread:receved msg type[47]\n" 
"[739:247021] PHYThrad: DSPMsgQ Received: msg type is[130] and SFNSF [14997] [SFN:937 SF:5]\n" 
"[739:247059] START of MACThread:receved msg type[47]") 

matches = re.finditer(regex, test_str, re.MULTILINE) 

for matchNum, match in enumerate(matches): 
    matchNum = matchNum + 1 

    print ("Match {matchNum} was found at {start}-{end}: {match}".format(matchNum = matchNum, start = match.start(), end = match.end(), match = match.group())) 

    for groupNum in range(0, len(match.groups())): 
     groupNum = groupNum + 1 

     print ("Group {groupNum} found at {start}-{end}: {group}".format(groupNum = groupNum, start = match.start(groupNum), end =  match.end(groupNum), group = match.group(groupNum))) 

Answer 5

斯蒂芬·劳赫给出的答案是很酷，但我认为你是python的新手，所以这里是一个基本功能。

考虑，“START”必须始终在消息的开始，而不是之间像，

[739:247021] PHYThrad: START DSPMsgQ Received: msg type is[130] and SFNSF [14997] [SFN:937 SF:5] # START at second index after split. 

如果我们考虑以上使用的情况下，这里是可以打印本"START"线功能在日志消息开始的文件中。

def getStart(filename): 
    with open(filename, "r") as reader: 
     for lines in reader.readlines(): # get list of lines 
      start = lines.split(' ')[1] # Split with space, and check the word is "START" 
      if start =='START': 
       print lines 

getStart("a.txt") # considering your filename is a.txt. 

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输出：

[739:246050] START of MACThread:receved msg type[47] 

[739:247059] START of MACThread:receved msg type[47]