This is the gr-digital package. It contains all of the digital
modulation blocks, utilities, and examples. To use the digital blocks,
the Python namespaces is in gnuradio.digital, which would be normally
imported as:

    from gnuradio import digital

See the Doxygen documentation for details about the blocks available
in this package. A quick listing of the details can be found in Python
after importing by using: 

    help(digital)