如何确定文件或目录是否存在？

import os

# 判断文件是否存在
if os.path.exists('/path/to/file.txt'):
    print("文件存在")
else:
    print("文件不存在")

# 判断目录是否存在
if os.path.exists('/path/to/directory'):
    print("目录存在")
else:
    print("目录不存在")

# 判断文件是否存在
ls /path/to/file.txt

# 判断目录是否存在
ls /path/to/directory

from qcloud_cos import CosConfig
from qcloud_cos import CosS3Client

# 配置腾讯云COS
secret_id = 'your-secret-id'
secret_key = 'your-secret-key'
region = 'your-region'
config = CosConfig(Region=region, SecretId=secret_id, SecretKey=secret_key)
client = CosS3Client(config)

# 判断文件是否存在
response = client.head_object(
    Bucket='your-bucket',
    Key='path/to/file.txt'
)
if response['ResponseMetadata']['HTTPStatusCode'] == 200:
    print("文件存在")
else:
    print("文件不存在")

# 判断目录是否存在
response = client.list_objects(
    Bucket='your-bucket',
    Prefix='path/to/directory/'
)
if 'Contents' in response:
    print("目录存在")
else:
    print("目录不存在")