How to receive a file with an Aws Lambda (python)

You are using API Gateway so your lambda event will map to something like this (from Amazon Docs):

{    "resource": "Resource path",    "path": "Path parameter",    "httpMethod": "Incoming request's method name"    "headers": {String containing incoming request headers}    "multiValueHeaders": {List of strings containing incoming request headers}    "queryStringParameters": {query string parameters }    "multiValueQueryStringParameters": {List of query string parameters}    "pathParameters":  {path parameters}    "stageVariables": {Applicable stage variables}    "requestContext": {Request context, including authorizer-returned key-value pairs}    "body": "A JSON string of the request payload."    "isBase64Encoded": "A boolean flag to indicate if the applicable request payload is Base64-encode"}

You can pass the file as a base64 value in the body and decode it in your lambda function. Take the following Python snippet

def lambda_handler(event, context):    data = json.loads(event['body'])    # Let's say we user a regular <input type='file' name='uploaded_file'/>    encoded_file = data['uploaded_file']    decoded_file = base64.decodestring(encoded_file)    # now save it to S3