import os
import errno
import boto3
import botocore


resource = boto3.resource('s3')
bucket = resource.Bucket('my-bucket')
client = boto3.client('s3')

def download_dir():
objList = client.list_objects(Bucket='my-bucket')['Contents']
for obj in objList:
    obj_Key = obj['Key']
    path,_destPath = os.path.split(obj_Key)
    print ("Downloading file :"+ obj_Key);
    client.download_file('my-bucket', obj_Key, _destPath)

download_dir()