cos_metadata_set.py

import boto3
from botocore.client import Config
s3 = boto3.resource(
    's3',
    # Hard coded strings as credentials, not recommended.
    aws_access_key_id='',
    aws_secret_access_key='',
    endpoint_url='https://cos.ap-beijing.myqcloud.com',
    config=Config(signature_version='s3v4')
)

bucket = s3.Bucket('bb')
key = bucket.Object('test')
key.put(Body='try try try', Metadata={
    'python-version': '3.7',
    'name': 'test',
    'version': '1.0.1',
    'Summary': "A super-fast templating language that borrows the best ideas  from the existing templating languages.",
  # 上面的summary 中 ideas  from 中间有两个空格
})
k = bucket.Object('test')
print(k.get())