Add alternative lookup syntax for namespaces v[1] instead of v(1). This works better when keys are tuples: v[1, 2] vs. v((1,2)). Also implement __contains__ so the in operator can be used instead of has_variable(). Add additional documentation on the use of namespaces.
Add alternative lookup syntax for namespaces
v[1]instead ofv(1). This works better when keys are tuples:v[1, 2]vs.v((1,2)). Also implement__contains__so theinoperator can be used instead ofhas_variable(). Add additional documentation on the use of namespaces.