chore: import upstream snapshot with attribution

tools/Polygraphy/examples/api/README.md

@@ -0,0 +1,64 @@
+# Polygraphy Python API Examples
+
+This directory includes examples that use the Polygraphy Python API.
+For examples of the command-line tools, see the [cli](../cli/) directory instead.
+
+You may find it useful to read the [Python API Overview](../../polygraphy/) prior
+to looking at the API examples.
+
+## Generating Your Own Examples
+
+In the event that the examples here do not cover a particular use-case, you can typically
+use `polygraphy run` to fill the gap; `polygraphy run` is capable of dynamically generating
+Python scripts that use the Polygraphy API that do exactly what the tool would otherwise do.
+
+Thus, if `polygraphy run` includes functionality you need, but you cannot find a
+corresponding API example, try running:
+```bash
+polygraphy run --gen - <options...>
+```
+The argument to `--gen` should be the name of the file in which to write the generated script.
+The special value `-` corresponds to `stdout`.
+
+For example, running:
+```bash
+polygraphy run --gen - model.onnx --trt --onnxrt
+```
+will display something like this on `stdout`:
+```py
+#!/usr/bin/env python3
+# Template auto-generated by polygraphy [v0.31.0] on 01/01/20 at 10:10:10
+# Generation Command: polygraphy run --gen - model.onnx --trt --onnxrt
+# This script compares model.onnx between TensorRT and ONNX-Runtime
+
+from polygraphy.logger import G_LOGGER
+
+from polygraphy.backend.onnxrt import OnnxrtRunner, SessionFromOnnx
+from polygraphy.backend.trt import EngineFromNetwork, NetworkFromOnnxPath, TrtRunner
+from polygraphy.comparator import Comparator
+import sys
+
+# Loaders
+parse_network_from_onnx = NetworkFromOnnxPath('model.onnx')
+build_engine = EngineFromNetwork(parse_network_from_onnx)
+build_onnxrt_session = SessionFromOnnx('model.onnx')
+
+# Runners
+runners = [
+    TrtRunner(build_engine),
+    OnnxrtRunner(build_onnxrt_session),
+]
+
+# Runner Execution
+results = Comparator.run(runners)
+
+success = True
+# Accuracy Comparison
+success &= bool(Comparator.compare_accuracy(results))
+
+# Report Results
+cmd_run = ' '.join(sys.argv)
+if not success:
+    G_LOGGER.critical(f"FAILED | Command: {cmd_run}"))
+G_LOGGER.finish(f"PASSED | Command: {cmd_run}"))
+```