你可以用Boto3。

import boto3
s3 = boto3.resource('s3')
bucket = s3.Bucket('my-bucket')
objs = list(bucket.objects.filter(Prefix=key))
if(len(objs)>0):
    print("key exists!!")
else:
    print("key doesn't exist!")

Here键是你要检查的路径是否存在

有一种简单的方法可以检查文件是否存在于S3桶中。我们不需要为此使用异常

sesssion = boto3.Session(aws_access_key_id, aws_secret_access_key)
s3 = session.client('s3')

object_name = 'filename'
bucket = 'bucketname'
obj_status = s3.list_objects(Bucket = bucket, Prefix = object_name)
if obj_status.get('Contents'):
    print("File exists")
else:
    print("File does not exists")

您可以使用awswrangler在一行中完成它。

awswrangler.s3.does_object_exist(path_of_object_to_check)

https://aws-data-wrangler.readthedocs.io/en/stable/stubs/awswrangler.s3.does_object_exist.html

does_object_exist方法使用s3客户机的head_object方法并检查是否引发了ClientError。如果错误代码是404，则返回False。

FWIW，这里是我正在使用的非常简单的函数

import boto3

def get_resource(config: dict={}):
    """Loads the s3 resource.

    Expects AWS_ACCESS_KEY_ID and AWS_SECRET_ACCESS_KEY to be in the environment
    or in a config dictionary.
    Looks in the environment first."""

    s3 = boto3.resource('s3',
                        aws_access_key_id=os.environ.get(
                            "AWS_ACCESS_KEY_ID", config.get("AWS_ACCESS_KEY_ID")),
                        aws_secret_access_key=os.environ.get("AWS_SECRET_ACCESS_KEY", config.get("AWS_SECRET_ACCESS_KEY")))
    return s3


def get_bucket(s3, s3_uri: str):
    """Get the bucket from the resource.
    A thin wrapper, use with caution.

    Example usage:

    >> bucket = get_bucket(get_resource(), s3_uri_prod)"""
    return s3.Bucket(s3_uri)


def isfile_s3(bucket, key: str) -> bool:
    """Returns T/F whether the file exists."""
    objs = list(bucket.objects.filter(Prefix=key))
    return len(objs) == 1 and objs[0].key == key


def isdir_s3(bucket, key: str) -> bool:
    """Returns T/F whether the directory exists."""
    objs = list(bucket.objects.filter(Prefix=key))
    return len(objs) > 1

看看

bucket.get_key(
    key_name, 
    headers=None, 
    version_id=None, 
    response_headers=None, 
    validate=True
)

检查bucket中是否存在特定的键。这个方法 使用HEAD请求来检查密钥是否存在。返回: Key对象或None的实例

从Boto S3文档

你可以调用bucket.get_key(keyname)并检查返回的对象是否为None。

试试这个简单的方法

import boto3
s3 = boto3.resource('s3')
bucket = s3.Bucket('mybucket_name') # just Bucket name
file_name = 'A/B/filename.txt'      # full file path
obj = list(bucket.objects.filter(Prefix=file_name))
if len(obj) > 0:
    print("Exists")
else:
    print("Not Exists")