import re
regex = re.compile(r"^(?:\d+(?:\|\d+)*,)+\d+(?:\|\d+)*$", flags=re.MULTILINE)
test_str = ("111|222,333,444\n\n"
"111\n"
"111,222|333,\n"
"111,222,333|\n"
",111,222,333|444\n"
"|111,222|333,444\n\n"
"111,222|333|333|444,444\n"
"111|222,333,444")
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