This diagram illustrates the communication paths used with pyCGNS.

On the right is the end-user Python script. It creates the Python/CGNS tree (i.e., file) in memory, and communicates with pyCGNS. Other user applications, such as a numeric process or MPI, may also make use of the Python/CGNS tree.

pyCGNS uses the CGNS Mid-Level Library to create an in-memory version of its own version of the tree. Using ADF (or HDF5) the Mid-Level Library also creates the actual CGNS file.

The logical data model (i.e., the SIDS) is unchanged.