sys is the interaction and the python interpreter to do
sys.path ---- order module to find
sys.path.append ()
sys.path.insert ()
sys.argv --- can only be executed in a terminal
sys.argv-- can only be executed in a terminal
print (sys.argv) --- instead of the input function
sys.modules-- view loaded into memory modules
print(sys.modules)
sys.platform-- view the current operating system platform
print(sys.platform)
sys.version --- see the current version of the interpreter
print(sys.version)