Added clarification that this library is specifically for the LSM303DLHC, which has the Y and Z magnetic orientations swapped from the LSM303DLH proper. Thanks tekktrik!
To use in CircuitPython, simply install the [Adafruit CircuitPython Bundle](https://circuitpython.org/libraries).
To use in CPython, `pip3 install adafruit-circuitpython-lsm303dlh-mag`.
Read the [docs](http://circuitpython.readthedocs.io/projects/lsm303dlh-mag/en/latest/) for info on how to use it.