python - 根据关键字python拆分文本字符串

Question

我有一串这样的文本:

'tx cycle up.... down
rx cycle up.... down
phase:...
rx on scan: 123456
tx cycle up.... down
rx cycle up.... down
phase:...
rx on scan: 789012
setup
tx cycle up.... down
rx cycle up.... down
tx cycle up.... down
rx cycle up.... down'

我需要将这个字符串拆分成一个字符串列表，这些字符串被拆分成这些 block :

['tx cycle up.... down rx cycle up.... down phase:.... rx on scan: 123456', 
 'tx cycle up.... down rx cycle up.... down phase:.... rx on scan: 789012',
 'tx cycle up... down rx cycle up.... down',
 'tx cycle up... down rx cycle up.... down']

有时他们有一个“阶段”和“扫描”数字，但有时他们没有，我需要这足够通用以适用于任何这些情况，并且必须对大量数据执行此操作。

基本上，我想将其拆分为一个字符串列表，其中每个元素从出现的“tx”延伸到下一个“tx”(包括第一个“tx”，但不包括该元素中的下一个)。我该怎么做？

编辑:假设除了上面的文本字符串之外，我还有其他如下所示的文本字符串:

'closeloop start
closeloop ..up:677 down:098
closeloop start
closeloop ..up:568 down:123'

我的代码遍历每个文本字符串并使用拆分代码将其拆分为列表。但是当它到达这串文本时，它找不到任何要拆分的内容——所以我如何包含一个命令来拆分“closeloop start”行(如果它们出现)和 tx 行(如果它们出现)？我试过这段代码，但出现类型错误:

data = re.split(r'\n((?=tx)|(?=closeloop\sstart))', data)

Answer 1

您可以拆分后跟 tx 的换行符:

import re

re.split(r'\n(?=tx)', inputtext)

演示:

>>> import re
>>> inputtext = '''tx cycle up.... down
... rx cycle up.... down
... phase:...
... rx on scan: 123456
... tx cycle up.... down
... rx cycle up.... down
... phase:...
... rx on scan: 789012
... setup
... tx cycle up.... down
... rx cycle up.... down
... tx cycle up.... down
... rx cycle up.... down'''
>>> re.split(r'\n(?=tx)', inputtext)
['tx cycle up.... down\nrx cycle up.... down\nphase:...\nrx on scan: 123456', 'tx cycle up.... down\nrx cycle up.... down\nphase:...\nrx on scan: 789012\nsetup', 'tx cycle up.... down\nrx cycle up.... down', 'tx cycle up.... down\nrx cycle up.... down']
>>> from pprint import pprint
>>> pprint(_)
['tx cycle up.... down\nrx cycle up.... down\nphase:...\nrx on scan: 123456',
 'tx cycle up.... down\nrx cycle up.... down\nphase:...\nrx on scan: 789012\nsetup',
 'tx cycle up.... down\nrx cycle up.... down',
 'tx cycle up.... down\nrx cycle up.... down']

但是，如果您只是循环遍历输入文件对象(逐行读取)，您可以在收集行时处理每个 block :

section = []
for line in open_file_object:
    if line.startswith('tx'):
        # new section
        if section:
            process_section(section)
        section = [line]
    else:
        section.append(line)
if section:
    process_section(section)

如果您需要匹配多个起始行，请将每个起始行作为 | 分隔的替代项包含在前瞻中:

data = re.split(r'\n(?=tx|closeloop\sstart)', data)