AWS 'Hello World!'

aws.py

#!/usr/bin/env python

import time
import hmac
import hashlib
import base64
import urllib

secret_key = "XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX"


def search(keywords):
    params = {
        "AWSAccessKeyId": "XXXXXXXXXXXXXXXXXXXX",
        "AssociateTag":   "",
        "Keywords":       urllib.quote(keywords),
        "Operation":      "ItemSearch",
        "ResponseGroup":  urllib.quote("ItemAttributes,Images"),
        "SearchIndex":    "",
        "Service":        "AWSECommerceService",
        # timestamp must be ISO 8601, GMT, and url-safe
        "Timestamp":      time.strftime("%Y-%m-%dT%H%%3A%M%%3A%SZ", time.gmtime()),
        "Version":        "2009-11-01"
    }

    # parameters must be sorted
    sorted = params.keys()
    sorted.sort()

    to_sign = "GET\necs.amazonaws.com\n/onca/xml\n"

    # make a url string with params ('&param=value')
    params_req = ""
    first = True
    for j in sorted:
        if(first):
            params_req += "%s=%s" % (j, params[j])
            first = False
        else:
            params_req += "&%s=%s" % (j, params[j])

    to_sign += params_req

    # sign string with SHA256
    signature = hmac.new(
        secret_key, msg=to_sign, digestmod=hashlib.sha256
    ).digest()
    signature = base64.b64encode(signature).decode()

    # url encode signature
    signature = urllib.quote(signature)

    # make request URL, including signature
    url_request = "http://ecs.amazonaws.com/onca/xml?%s&Signature=%s" % (
        params_req, signature
    )

    return urllib.urlopen(url_request)