regex url required and optional

```python
import re

regex_required = re.compile(r'^https://example.com/(?P<var>\d+)$')
sre_match = regex_required.match('https://example.com/123')
sre_match.group('var')

regex_optional = re.compile(r'^https://example.com/(?P<var>\d+|\*)')
sre_match = regex_optional.match('https://example.com/*')
sre_match.group('var')
```