import re
regex = re.compile(r"^\s*\S*\w*\W*(?<severity>\w)(?<time>\d{4}\s[^\s]*)\s+(?<pid>\d+)\s+(?<source>[^ \]]+)\](?<message>.*\n)", flags=re.MULTILINE)
test_str = ("{\"log\":\"I1121 14:37:42.883962 1 serve.go:85] Serving securely on 0.0.0.0:6443\\n\",\"stream\":\"stderr\",\"time\":\"2017-11-21T14:37:42.902231562Z\"}\n"
"{\"log\":\"I1121 14:37:42.885062 1 apiservice_controller.go:112] Starting APIServiceRegistrationController\\n\",\"stream\":\"stderr\",\"time\":\"2017-11-21T14:37:42.902266652Z\"}\n"
"{\"log\":\"I1121 14:37:42.885079 1 cache.go:32] Waiting for caches to sync for APIServiceRegistrationController controller\\n\",\"stream\":\"stderr\",\"time\":\"2017-11-21T14:37:42.902269685Z\"}\n"
"{\"log\":\"I1121 14:37:42.886031 1 available_controller.go:192] Starting AvailableConditionController\\n\",\"stream\":\"stderr\",\"time\":\"2017-11-21T14:37:42.902271525Z\"}\n"
"{\"log\":\"I1121 14:37:42.886043 1 cache.go:32] Waiting for caches to sync for AvailableConditionController controller\\n\",\"stream\":\"stderr\",\"time\":\"2017-11-21T14:37:42.902273437Z\"}\n"
" {\"log\":\"E0213 13:30:06.573154 1 cleaner.go:100] Error while attempting to clean CSR \"csr-4nzcx\": unable to delete CSR \\\\\\\"csr-4nzcx\\\\\\\": certificatesigningrequests.certificates.k8s.io \\\\\\\"csr-4nzcx\\\\\\\" is forbidden: User \\\\\\\"system:serviceaccount:kube-system:certificate-controller\\\\\\\" cannot delete certificatesigningrequests.certificates.k8s.io at the cluster scope\\\\n\\\",\\\"stream\\\":\\\"stderr\\\",\\\"time\\\":\\\"2018-02-13T13:30:06.575560335Z\\\"}\"\n"
"\"log\": \"I0213 17:07:12.217422 1 trace.go:76] Trace[120533389]: \\\"Create /api/v1/namespaces/default/events\\\" (started: 2018-02-13 17:07:08.211886864 +0000 UTC m=+8.804410052) (total time: 4.005504088s):\\n\",\n\n")
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