Python RegEx for all National Drug Codes (NDC 10 & 11) formats

Goal: RegEx to fit many posible NDC 10 & 11 formats.

I’ve made a great start…
NDC 10:

^[0-9][0-9][0-9][0-9]\-[0-9][0-9][0-9][0-9]\-[0-9][0-9]$

e.g. 1234-1234-12
Reference

However, I’ve since learnt there are other formats and 11 digits:

• 4-4-2
• 5-3-2
• 5-4-1
• 5-4-2 (11 digits)

How can I write one RegEx for all these possibilities?

Issues:

1. Optional 11th digit,
2. Moving hyphen

>Solution :

You can use

^(?:\d{4}-\d{4}-\d{2}|\d{5}-(?:\d{3}-\d{2}|\d{4}-\d{1,2}))$

See the regex demo. Details:

• ^ – start of string
• (?: – start of the first non-capturing group:
  • \d{4}-\d{4}-\d{2} – four digits, -, four digits, -, two digits
  • | – or
  • \d{5}- – five digits, -
  • (?: – start of the second non-capturing group:
    • \d{3}-\d{2} – three digits, -, two digits
    • | – or
    • \d{4}-\d{1,2} – four digits, - and one or two digits
  • ) – end of the second non-capturing group
• ) – end of the first non-capturing group.
• $ – end of string.