Hmmm… BitMask32 has no documentation in the API docs. But lucky us we are using Python, and Python has --tada-- introspection. Try this:
from pandac.PandaModules import BitMask32
print dir( BitMask32 )
This should be enough documentation. If not, go on like this:
print BitMask32.allOn( )
print BitMask32.allOff( )
o = BitMask32( )
print o
o.setBit( 16 )
o.setBit( 12 )
o.setBit( 19 )
print o
enn0x