Regular Expressions 101

Explanation
Pro

Group day(?P<day>\d\d)

\da Unicode decimal digit

.any Unicode character (except for line terminators)

Group month(?P<month>\d\d)

\da Unicode decimal digit

.any Unicode character (except for line terminators)

Group year(?P<year>\d{4})

\d{4}a Unicode decimal digit, repeated exactly 4 times

_the literal _ (95₁₀ / 137₈ / 5F₁₆)

Global pattern flags

g modifier: global. Finds all matches instead of stopping after the first

Detailed match information will be displayed here automatically.

25 tokens

(?P<day>\d\d).(?P<month>\d\d).(?P<year>\d{4})_

28.09.2017_SD1_to_orcam_bills_10indian