import re
regex = re.compile(r"(?m)^(\d{2}:\d{2}:\d{2}\.\d+) +--> +(\d{2}:\d{2}:\d{2}\.\d+).*[\r\n]+\s*(?s)((?:(?!\r?\n\r?\n).)*)")
test_str = ("00:00:02.736 --> 00:00:06.072 line:79.33% position:10.00% align:start \n"
" AND YOUR GRACE?\n\n"
"00:00:06.072 --> 00:00:08.875 line:74.00% position:10.00% align:start \n"
" WHAT WILL YOU DO\n"
" ABOUT THAT?")
subst = "|"
result = regex.sub(subst, test_str)
if result:
print(result)
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for Python, please visit: https://docs.python.org/3/library/re.html