python

General Setup Guide for Samples

Download Sample Data

Install the tool dependencies via python3 -m pip install -r requirements.txt.

Invoke downloader.py to download the data with a command like the one below if download.yml is present in the sample directory (example).

downloader.py -d /path/to/data/dir -f /path/to/download.yml

The data directory i.e. /path/to/data/dir is a centralized directory to store data of all samples. So you can use same one for all samples. It can be provided by either -d /path/to/data/dir or the environment variable $TRT_DATA_DIR, where the -d has higher priority.

Remember to use -d or $TRT_DATA_DIR when running sample scripts that rely on downloaded data. Scripts will abort if no downloaded data is found in data directory. ($TRT_DATA_DIR will be much simplier.) An error will be thrown if the data is not properly setup.

The download.yml file is owned by the sample which describes the sample name, the path, URL and checksum of the data files that are required by the sample.

Notes for sample developers

To use the downloaded data files, integrate the code segment like below into the sample code, and obtain the path to the data file by passing the path as specified in the associated download.yml file of the sample.

TRT_DATA_DIR = None

def getFilePath(path):
    global TRT_DATA_DIR
    if not TRT_DATA_DIR:
        parser = argparse.ArgumentParser(description="Convert YOLOv3 to ONNX model")
        parser.add_argument('-d', '--data', help="Specify the data directory where it is saved in. $TRT_DATA_DIR will be overwritten by this argument.")
        args, _ = parser.parse_known_args()
        TRT_DATA_DIR = os.environ.get('TRT_DATA_DIR', None) if args.data is None else args.data
    if TRT_DATA_DIR is None:
        raise ValueError("Data directory must be specified by either `-d $DATA` or environment variable $TRT_DATA_DIR.")

    fullpath = os.path.join(TRT_DATA_DIR, path)
    if not os.path.exists(fullpath):
        raise ValueError("Data file %s doesn't exist!" % fullpath)

    return fullpath

The helper function getFilePath in downloader.py can also be used to obtain the full path to the downloaded data files. It only works when the sample doesn't have any other command line argument.

from downloader import getFilePath

cfg_file_path = getFilePath('samples/python/yolov3_onnx/yolov3.cfg')

Python Version Support

All Python samples are expected to be run with Python>=3.8. It is not recommended to use any lower version as there may be compatibility issues.