Measuring inductance is difficult, especially since a guitar pickup has an L, an R, and a C, like OTM said. I'm not aware of a simple method.

I also agree with fuzzy that the inductance is a fairly good indicator of the characteristic of a pickup, so it really helps to know it. In the case of BLs, I had the idea of creating a sticky thread which lists the resistances of BL pickups. Then, people can compare their measurements with the reference values and determine what pickup they have.

We'll have to work out the details with Nigel. IMO it's important to have a disclaimer in such a thread that the DC resistance is only useful for comparison with the reference values. It doesn't tell anything about the transfer characteristics, contrary to popular belief.
Let the thunder roll and the lightning flash, I'm doing alright for country trash.