nvidia--tensorrt/tools/Polygraphy/polygraphy/tools/args/README.md

Command-Line Argument Groups

Introduction

The Polygraphy command-line toolkit includes several tools, many of which require the same or similar functionality as other tools. To facilitate efficient code reuse, commonly used functionality is bundled into reusable components, which we'll refer to as Argument Groups.

Argument Groups

An Argument Group combines a set of command-line options, parsing logic, and functionality related to those arguments. The interface is defined in BaseArgs. The most commonly used methods are:

• add_parser_args(self, parser): Adds options to an argparse argument parser.

• parse(self, args): Parses command-line arguments from the args object created by argparse and populates attributes in the argument group. For simple arguments, this amounts to assigning an attribute of the argument group to a corresponding attribute in the args object. For more complex arguments, such as input shapes, this may involve more complex parsing.

• add_to_script(self, script): Adds code to a Python script that will provide functionality related to the argument group. For example, OnnxLoadArgs, which is responsible for loading ONNX models, may populate the script with a OnnxFromPath loader.

  NOTE: You may be wondering why we add code to a script instead of just providing a method that will perform the relevant function, e.g. load_onnx in this case. The reason is that adding to a script allows tools like polygraphy run to compose together complex behavior and generate Python scripts which can be edited and used for more advanced needs.

Many of the argument groups also provide immediately evaluated helper methods, such as load_onnx() in the case of OnnxLoadArgs, which can be used by tools that do not need to generate scripts. These helpers typically use the run_script method from polygraphy.tools.args.util to reuse the logic from their add_to_script method.

Usage

Tools can subscribe to argument groups by implementing the get_subscriptions() interface defined in tool.py. This will add all the command-line options provided by the argument group to the tool, and these will be parsed automatically before the tool's run method is called. The tool can then access the argument groups via self.arg_groups.

For details, see the example.