Even though nightlife is general term all kind of entertainment available in night.
Normally, nightlife is quite popular in metropolitan cities like Lahore.
When this word comes into mind lots of bars, night clubs, pubs and parties comes into mind. If you mean pubs and clubs by nightlife then there is no night life in Lahore.
Pakistan is Islamic republic alcohol is banned along with nightclubs. Nightlife is more adult-oriented in western countries which different story in this country..
Consumption of alcohol is permitted to non-Muslims but its availability is a major issue it is really hard to find alcohol for them. Similar thing for parties there are no parties in the Lahore. It is separate thing if you can find a private party, which are commonly known as underground parties. These underground parties have limited access to elite class or riches only.
On other side of the picture there is hidden prostitution i.e. Hira Mandi. Which also comes with great risk because it is also illegal.
On the bright side you can go and enjoy Pakistani cuisine and cultural folk music with Sufi background. You can also enjoy the shisha smoking which is also banned in some places but you can find it with little effort. The best advice would be to have a local guide who will help you finding the real Lahore if you are an outsider. Lots of good sandwiches are also available in Lahore city.
Underground Party in Lahore