upload file to s3 and read file


I am trying to upload excel (.xlsx) file to s3 and read and extract data to save in DB In my local machine code is working fine when I deployed to lambda then this error is raised raise BadZipFile("Bad magic number for central directory")

API tool: fastapi language: python to read file openpyxl library is used


def upload_file_to_s3(file: UploadFile, S3_BUCKET, S3_KEY):
        s3 = boto3.client('s3', aws_access_key_id=AWS_ACCESS_KEY, aws_secret_access_key=AWS_SECRET_KEY)

        # Create a BytesIO object from the file contents
        # file_contents = file.file.read()
        # file_like_object = BytesIO(file_contents)

        # Upload the file to S3 bucket
        response = s3.upload_fileobj(file.file, S3_BUCKET, S3_KEY)
        return response
    except NoCredentialsError:
        raise HTTPException(status_code=status.HTTP_500_INTERNAL_SERVER_ERROR, detail='No AWS credentials found')

@route.post("/uploadfile/", tags=["contact details"], dependencies=[Depends(check_active)])
def create_upload_file(file: UploadFile, promotionName:str = Form(...),promotionId:str = Form(...)):
        # Initialize Boto3 S3 client
        upload_file_to_s3(file=file, S3_BUCKET="catalog-naveen", S3_KEY=file.filename)
        key = file.filename
        # Load the Excel file from S3
        s3 = boto3.client('s3', aws_access_key_id=AWS_ACCESS_KEY, aws_secret_access_key=AWS_SECRET_KEY)
        obj = s3.get_object(Bucket="catalog-naveen", Key=key)
        excel_data = obj['Body'].read()

        # Create a BytesIO object from the Excel data
        # file_like_object = BytesIO(excel_data)
        # print("######",file_like_object)

        wb = load_workbook(filename=BytesIO(excel_data), read_only=True, data_only=True)
        # Get the first worksheet
        sheet = wb.active
        rows = []
        # Iterate over each row in the worksheet
        for row in sheet.iter_rows(values_only=True):
        batch_size = len(rows)+1
        # print("#############",len(rows)+1)
        for i in range(1, len(rows), batch_size):
            batch = rows[i:i+batch_size]
            # guest = contactDetailsModel( guestName=i[1], guestNumber=i[2], promotionName=event)
            guest = [contactDetailsModel(contactName=row[1], contactNumber=row[2], promotionName=promotionName, promotionId=promotionId) for row in batch]

            # print("#######", i[1])
        # Return the extracted rows
        return {"created"}
    except Exception as e:
        raise HTTPException(status_code=status.HTTP_500_INTERNAL_SERVER_ERROR, detail= e)

complete error from CloudWatch

Traceback (most recent call last):
  File "/var/task/routes/event.py", line 71, in create_upload_file
    wb = load_workbook(filename=file_like_object, read_only=True, data_only=True)
  File "/var/task/openpyxl/reader/excel.py", line 344, in load_workbook
    reader = ExcelReader(filename, read_only, keep_vba,
  File "/var/task/openpyxl/reader/excel.py", line 123, in __init__
    self.archive = _validate_archive(fn)
  File "/var/task/openpyxl/reader/excel.py", line 95, in _validate_archive
    archive = ZipFile(filename, 'r')
  File "/var/lang/lib/python3.10/zipfile.py", line 1269, in __init__
  File "/var/lang/lib/python3.10/zipfile.py", line 1366, in _RealGetContents
    raise BadZipFile("Bad magic number for central directory")
zipfile.BadZipFile: Bad magic number for central directory

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/var/task/starlette/middleware/exceptions.py", line 68, in __call__
    await self.app(scope, receive, sender)
  File "/var/task/fastapi/middleware/asyncexitstack.py", line 20, in __call__
    raise e
  File "/var/task/fastapi/middleware/asyncexitstack.py", line 17, in __call__
    await self.app(scope, receive, send)
  File "/var/task/starlette/routing.py", line 718, in __call__
    await route.handle(scope, receive, send)
  File "/var/task/starlette/routing.py", line 276, in handle
    await self.app(scope, receive, send)
  File "/var/task/starlette/routing.py", line 66, in app
    response = await func(request)
  File "/var/task/fastapi/routing.py", line 241, in app
    raw_response = await run_endpoint_function(
  File "/var/task/fastapi/routing.py", line 169, in run_endpoint_function
    return await run_in_threadpool(dependant.call, **values)
  File "/var/task/starlette/concurrency.py", line 41, in run_in_threadpool
    return await anyio.to_thread.run_sync(func, *args)
  File "/var/task/anyio/to_thread.py", line 33, in run_sync
    return await get_asynclib().run_sync_in_worker_thread(
  File "/var/task/anyio/_backends/_asyncio.py", line 877, in run_sync_in_worker_thread
    return await future
  File "/var/task/anyio/_backends/_asyncio.py", line 807, in run
    result = context.run(func, *args)
  File "/var/task/routes/event.py", line 92, in create_upload_file
    raise HTTPException(status_code=status.HTTP_500_INTERNAL_SERVER_ERROR, detail= e)

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/var/task/mangum/protocols/http.py", line 58, in run
    await app(self.scope, self.receive, self.send)
  File "/var/task/fastapi/applications.py", line 290, in __call__
    await super().__call__(scope, receive, send)
  File "/var/task/starlette/applications.py", line 122, in __call__
    await self.middleware_stack(scope, receive, send)
  File "/var/task/starlette/middleware/errors.py", line 184, in __call__
    raise exc
  File "/var/task/starlette/middleware/errors.py", line 162, in __call__
    await self.app(scope, receive, _send)
  File "/var/task/starlette/middleware/cors.py", line 83, in __call__
    await self.app(scope, receive, send)
  File "/var/task/starlette/middleware/exceptions.py", line 88, in __call__
    response = await handler(request, exc)
  File "/var/task/fastapi/exception_handlers.py", line 15, in http_exception_handler
    return JSONResponse(
  File "/var/task/starlette/responses.py", line 196, in __init__
    super().__init__(content, status_code, headers, media_type, background)
  File "/var/task/starlette/responses.py", line 55, in __init__
    self.body = self.render(content)
  File "/var/task/starlette/responses.py", line 199, in render
    return json.dumps(
  File "/var/lang/lib/python3.10/json/__init__.py", line 238, in dumps
  File "/var/lang/lib/python3.10/json/encoder.py", line 199, in encode
    chunks = self.iterencode(o, _one_shot=True)
  File "/var/lang/lib/python3.10/json/encoder.py", line 257, in iterencode
    return _iterencode(o, 0)
  File "/var/lang/lib/python3.10/json/encoder.py", line 179, in default
    raise TypeError(f'Object of type {o.__class__.__name__} '
TypeError: Object of type BadZipFile is not JSON serializable
  • It would help to see the code here; the error message is not entirely helpful - it looks like you're passing an object (probably the Excel file) into something which is expecting JSON.

  • I have updated the question with code

  • I have a same issue. Have you solved?

3 Answers

I know the instructions in the re:Post article you've linked to talk about building the packages for alternate architectures; but as a just in case: Have you tried creating your Lambda ZIP file on an Amazon Linux instance that matches the architecture of the Lambda function (x64/arm)? Checking before I spend some time to try and recreate the issue that you're having.

profile pictureAWS
answered a year ago
  • Hi, I have forget to mention that I have different APIs in lambda and those are working fine, only issue with upload API

  • Ok - I'm not sure (as in confused) as to what problem you're trying to troubleshoot here.

  • when I am trying to upload a file with https API getting internal server error there error in reading xlsx file from s3

  • So are you getting the error when uploading (writing - PutObject) or when downloading (reading - GetObject)?

  • while reading


Hi, is the code of the Lambda deployed via zip file (given the error message) ? If yes, I would check this zip file: it may be corrupted and prevent proper deployment of the lambda. Best, Didier

profile pictureAWS
answered a year ago

What might be happening is that you're reading the file originally as an ASCII (i.e. non-binary) file and that might be messing with the conversion during the upload; which means that the file is corrupted and therefore the download fails.

In the original read (which is pseudocode here), ensure that you are doing a binary read; something like file = open('filename.xlsx', 'rb')

profile pictureAWS
answered 3 days ago

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