title: Reading Files from S3 Bucket to PySpark Dataframe Boto3
body: <p>How can I load a bunch of files from a S3 bucket into a single PySpark dataframe?  I'm running on an EMR instance. If the file is local, I can use the SparkContext textFile method. But when the file is on S3, how can I use boto3 to load multiple files of various types (CSV, JSON, ...) into a single dataframe for processing?</p>