Python使用本地文件而不是url参数

Question

我正在与Google视觉AI一起学习python，我想知道如何才能使此代码与本地图像一起运行，因为此时您必须运行“ python code.py URL参数”。我该如何使其加载本地目录中的文件？

import argparse
import io

from google.cloud import vision
from google.cloud.vision import types


def annotate(path):
    """Returns web annotations given the path to an image."""
    client = vision.ImageAnnotatorClient()

    if path.startswith('http') or path.startswith('gs:'):
        image = types.Image()
        image.source.image_uri = path

    else:
        with io.open(path, 'rb') as image_file:
            content = image_file.read()

        image = types.Image(content=content)

    web_detection = client.web_detection(image=image).web_detection

    return web_detection


    def report(annotations):
        """Prints detected features in the provided web annotations."""
        if annotations.pages_with_matching_images:
            print('\n{} Pages with matching images retrieved'.format(
                len(annotations.pages_with_matching_images)))

        for page in annotations.pages_with_matching_images:
            print('Url   : {}'.format(page.url))

    if annotations.full_matching_images:
        print('\n{} Full Matches found: '.format(
              len(annotations.full_matching_images)))

        for image in annotations.full_matching_images:
            print('Url  : {}'.format(image.url))

    if annotations.partial_matching_images:
        print('\n{} Partial Matches found: '.format(
              len(annotations.partial_matching_images)))

        for image in annotations.partial_matching_images:
            print('Url  : {}'.format(image.url))

    if annotations.web_entities:
        print('\n{} Web entities found: '.format(
              len(annotations.web_entities)))

        for entity in annotations.web_entities:
            print('Score      : {}'.format(entity.score))
            print('Description: {}'.format(entity.description))

if __name__ == '__main__':
    parser = argparse.ArgumentParser(
        description=__doc__,
        formatter_class=argparse.RawDescriptionHelpFormatter)
    path_help = str('The image to detect, can be web URI, '
                    'Google Cloud Storage, or path to local file.')
    parser.add_argument('image_url', help=path_help)
    args = parser.parse_args()

    report(annotate(args.image_url))

我已经尝试了很多更改，但是无论发生什么，仍然需要一个参数，这是Google API的规定吗？我以为它已经在代码的基础上获得了本地支持，但是我无法确定触发器到底是什么。每当我尝试运行不带URL参数的罐时，都会以我的方式抛出此错误。

“用法：visiontest.py [-h] image_url visiontest.py：错误：参数太少”