import re
regex = re.compile(r"(?<!\d[- \/.])(?<!\d)(3[01]|[12][0-9]|0?[1-9])[- \/.](1[012]|0?[1-9])[- \/.](?:\d{2})?(\d?\d)(?![- \/.]?\d)")
test_str = ("Correct:\n"
"01/01/2000\n"
"01/Jan/2000\n"
"31/01/2000\n"
"31/Jan/2000\n"
"31.Jan.2000\n"
"31-Jan-2000\n"
"01/1/2000 x form\n"
"01/Jan/2000\n"
"01/1/01 x form\n"
"01/Jan/01\n"
"29/02/2000 x date\n"
"29/Feb/2000\n"
"28/02/2001\n"
"28/Feb/2001\n"
"30/04/2000\n"
"30/Apr/2000\n"
"31/07/2000\n"
"31/Jul/2000\n"
"31/08/2000\n"
"31/Aug/2000\n"
"01/12/2000\n"
"01/Dec/2000\n\n"
"31-01-8888 ?\n"
"02/Jan-1984\n"
"1.1.0 x form\n"
"10.11.12\n\n"
"all catched as x form\n"
"0,0,0\n"
"test 31.100.1952\n"
"32/03/18\n"
"1.2.3\n"
"123.2.12\n"
"_22.02.18_\n"
"22-02-18test\n"
"22/02-18\n"
"22//02/18\n"
"22 02-18\n"
"22:02:18\n"
"1,2,3\n\n"
"False:\n"
"32/01/2000 x form\n"
"32/Jan/2000\n"
"01/15/2000 x form\n"
"29/02/2001 x date\n"
"29/Feb/2001\n"
"29/02/1900 x date\n"
"31/04/2000 x date\n"
"31/Apr/2000\n"
"31/09/2000 x date\n"
"31/Sep/2000\n"
"1.2.3-4\n"
"1-2-3.4\n"
"10.10.10.10\n"
"2w4w6\n\n"
"... falls on the date of 10.11.12.\n"
"... it.10.11.12 has some type - there should be a whitespace but ....")
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