import re
regex = re.compile(r"^\[([^\[]+\[){6}[^:]+:(?<id>[^\@]+)@(?<host>\S+)", flags=re.MULTILINE)
test_str = ("[01/05/2020 13:06:21] BAUAJM_I_30031 Client [CA WAAE Auto:15515][5][abc@hostname.com:50019:12.304.593.10] [0x80c91100][02/05/2020 13:06:21.8474][0:rmk123@abc.bbb.com@hostname.com 0] API ID [34] execution started.\n\n"
"[01/05/2020 13:06:21] BAUAJM_I_30032 Client [CA WAAE Auto:15509][5][bdc.ab.cpm@hostname.com:12345:19.304.293.10] [0x28bbbfff][02/05/2020 13:06:21.6946][0:rmc143@bdc.ab.cpm@hostname.com 0] API ID [66] execution completed. Total time: 0.132519 seconds.")
matches = regex.finditer(test_str)
for match_num, match in enumerate(matches, start=1):
print(f"Match {match_num} was found at {match.start()}-{match.end()}: {match.group()}")
for group_num, group in enumerate(match.groups(), start=1):
print(f"Group {group_num} found at {match.start(group_num)}-{match.end(group_num)}: {group}")
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