How to use Boto3 library in Python to upload an object in S3 using AWS Resource?

Boto3PythonServer Side ProgrammingProgramming

Problem Statement − Use Boto3 library in Python to upload an object into S3. For example, how to upload into Bucket_1 of S3.

Approach/Algorithm to solve this problem

Step 1 − Import boto3 and botocore exceptions to handle exceptions.

Step 2 − From pathlib, import PurePosixPath to retrive filename from path

Step 3s3_path and filepath are the two parameters in function upload_object_into_s3

Step 4 − Validate the s3_path is passed in AWS format as s3://bucket_name/key and filepath as local path C://users/filename

Step 5 − Create an AWS session using boto3 library.

Step 6 − Create an AWS resource for S3.

Step 7 − Split the S3 path and perform operations to separate the root bucket name and key path

Step 8 − Get the file name for complete filepath and add into S3 key path.

Step 9 − Now use the function upload_fileobj to upload the local file into S3.

Step 10 − Use the function wait_until_exists to wait until operation is finished.

Step 11 − Handle the exception based on response code to validate whether file is uploaded or not.

Step 12 − Handle the generic exception if something went wrong while uploading the file


Use the following code to upload a file into AWS S3 −

import boto3
from botocore.exceptions import ClientError
from pathlib import PurePosixPath

def upload_object_into_s3(s3_path, filepath):

   if 's3://' in filepath:
      print('SourcePath is not a valid path.' + filepath)
      raise Exception('SourcePath is not a valid path.')
   elif s3_path.find('s3://') == -1:
      print('DestinationPath is not a s3 path.' + s3_path)
      raise Exception('DestinationPath is not a valid path.')
   session = boto3.session.Session()
   s3_resource = session.resource('s3')
   tokens = s3_path.split('/')
   target_key = ""
   if len(tokens) > 3:
      for tokn in range(3, len(tokens)):
         if tokn == 3:
            target_key += tokens[tokn]
            target_key += "/" + tokens[tokn]
   target_bucket_name = tokens[2]

   file_name = PurePosixPath(filepath).name
   if target_key != '':
      key_path = target_key + "/" + file_name
      key_path = file_name
   print(("key_path: " + key_path, 'target_bucket: ' + target_bucket_name))

      # uploading Entity from local path
      with open(filepath, "rb") as file:
      s3_resource.meta.client.upload_fileobj(file, target_bucket_name, key_path)
         s3_resource.Object(target_bucket_name, key_path).wait_until_exists()
      except ClientError as error:
         error_code = int(error.response['Error']['Code'])
         if error_code == 412 or error_code == 304:
            print("Object didn't Upload Successfully ", target_bucket_name)
            raise error
      return "Object Uploaded Successfully"
   except Exception as error:
      print("Error in upload object function of s3 helper: " + error.__str__())
      raise error
print(upload_object_into_s3('s3://Bucket_1/testfolder', 'c://'))


key_path:/testfolder/, target_bucket: Bucket_1
Object Uploaded Successfully
Published on 22-Mar-2021 07:39:01