micropython/tests/extmod/ure_span.py

# test match.span(), and nested spans

try:
    import ure as re
except ImportError:
    try:
        import re
    except ImportError:
        print("SKIP")
        raise SystemExit

try:
    m = re.match(".", "a")
    m.span
except AttributeError:
    print("SKIP")
    raise SystemExit


def print_spans(match):
    print("----")
    try:
        i = 0
        while True:
            print(match.span(i), match.start(i), match.end(i))
            i += 1
    except IndexError:
        pass


m = re.match(r"(([0-9]*)([a-z]*)[0-9]*)", "1234hello567")
print_spans(m)

m = re.match(r"([0-9]*)(([a-z]*)([0-9]*))", "1234hello567")
print_spans(m)

# optional span that matches
print_spans(re.match(r"(a)?b(c)", "abc"))

# optional span that doesn't match
print_spans(re.match(r"(a)?b(c)", "bc"))