Hi, this is Kevin from PCI Geomatics.
Thanks for posting your questions. The link you posted seems to be broken (the Python documentation is not working). The updated documentation is available here:
Also, in the installation directory, you will find Python examples for all the algorithms that are executable within the Python environment. You will find these in the following folder:
C:\PCI Geomatics\Geomatica 2017\Examples\Python
The main atmospheric correction algorithm example is the file names "atcor.py" in this folder.
Let us know if you have any issues.