Example Lambda function

process.py

import boto3
import os
import subprocess
import uuid

libdir = os.path.join(os.getcwd(), 'lib')

import warnings
from astropy.utils.data import CacheMissingWarning
warnings.simplefilter('ignore', CacheMissingWarning)

from astropy.io import fits
import numpy as np
from photutils import datasets
from skimage import data

def do_science(event):
    file = event['fits_s3_key']
    bucket = event['fits_s3_bucket']

    root = drz_file.split('/')[-1].split('_')[0]

    # Create S3 session
    s3 = boto3.resource('s3')
    s3_client = boto3.client('s3')
    
    # Download the file from S3 (note this is free from Lambda as long as your 
    # function is executing in the US-East AWS region) and write out to tmp.
    bkt = s3.Bucket(bucket)
    bkt.download_file(file, '/tmp/{0}'.format(root), 
                      ExtraArgs={"RequestPayer": "requester"})

    # Open the FITS file and print some debug
    hdul = fits.open('/tmp/{0}'.format(root))
    print(hdul.info())

# Incoming event has the following structure:
#     event = {
#          'fits_s3_key': 'S3 key name',
#          'fits_s3_bucket': 'stpubdata',
#          's3_output_bucket': 'output-bucket' # optional
#        }
#
# 'process.handler' (this function) is what is called when the Lambda process spawns
def handler(event, context):
    print event['s3_output_bucket']
    print event['fits_s3_key']
    print event['fits_s3_bucket']
    do_science(event)

if __name__ == "__main__":
    handler('', '')