bbarchivist.networkutils

Complexity

Total Complexity

192

Size/Duplication

Total Lines	1669
Duplicated Lines	0 %

Test Coverage

Coverage

100%

Importance

Changes

0

80 Functions

Rating	Name	Duplication	Size	Complexity
B	download_bootstrap()	0	29	5
A	grab_pem()	0	10	3
B	ptcrb_item_cleaner()	0	41	2
A	loader_page_scraper_bbm()	0	13	2
A	remove_empty_download()	0	9	2
B	bulk_droid_skeletons()	0	26	4
A	table_header_filter()	0	9	1
B	download_writer()	0	29	4
A	droid_scanner()	0	21	3
B	make_droid_skeleton()	0	24	3
A	droid_scanner_worker()	0	19	3
A	get_length()	0	20	3
A	pem_wrapper()	0	14	1
A	base_metadata_url()	0	10	2
A	make_droid_skeleton_bbm()	0	23	2
A	prepare_droid_list()	0	12	2
A	chunker()	0	12	2
A	download()	0	21	1
A	space_pad()	0	13	2
A	ptcrb_cleaner_spaces()	0	14	3
A	root_generator()	0	22	2
A	loader_page_chunker_og()	0	18	2
B	try_try_again()	0	23	5
A	generic_session()	0	9	2
A	generic_soup_parser()	0	14	1
A	loader_page_chunker_bbm()	0	10	2
A	ptcrb_cleaner_multios()	0	12	2
A	unicode_filter()	0	8	1
A	loader_page_scraper_og()	0	13	2
A	devalpha_urls_bulk()	0	23	3
A	tcl_master()	0	5	1
A	table_headers()	0	9	3
A	dump_tcl_xml()	0	12	3
A	encrypt_header()	0	23	3
B	kernel_scraper()	0	23	4
A	loader_page_printer()	0	11	1
A	encrypt_header_prep()	0	15	2
B	vkhash()	0	34	1
A	series_generator()	0	9	1
A	getcode()	0	18	2
A	ptcrb_scraper()	0	21	3
B	download_request_prep()	0	37	2
B	tcl_check()	0	32	3
A	dev_dupe_remover()	0	15	4
A	availability()	0	14	1
A	unpack_vdkey()	0	7	1
B	parse_carrier_xml()	0	22	4
A	parse_tcl_download_request()	0	17	2
A	remote_prd_info()	0	10	3
A	devalpha_urls()	0	23	2
B	tcl_download_request()	0	44	3
A	parse_tcl_check()	0	15	1
A	carrier_checker()	0	22	1
B	make_droid_skeleton_og()	0	27	2
A	cchecker_get_tags()	0	13	4
A	tcl_default_id()	0	10	2
B	carrier_child_finder()	0	26	5
A	loader_page_scraper()	0	11	1
A	sim_metadata()	0	10	1
A	dev_dupe_cleaner()	0	11	3
A	download_android_tools()	0	17	4
A	return_npc()	0	11	1
A	devalpha_urls_bootstrap()	0	18	3
A	carrier_query()	0	62	3
B	check_prep()	0	32	1
A	sr_lookup_extractor()	0	14	4
B	sr_lookup()	0	36	1
A	base_metadata()	0	17	3
A	sr_lookup_xmlparser()	0	14	3
A	sr_lookup_poster()	0	22	3
A	tcl_salt()	0	7	1
B	available_bundle_lookup()	0	41	2
A	devalpha_urls_serieshandler()	0	15	3
A	carrier_child_fileappend()	0	22	3
A	ndk_metadata()	0	11	3
A	carrier_swver_get()	0	10	2
B	sr_lookup_bootstrap()	0	30	5
A	runtime_metadata()	0	10	1
A	clean_availability()	0	14	3
A	dev_dupe_dicter()	0	11	2

#!/usr/bin/env python3

Too many lines in module (1668/1000)

"""This module is used for network connections; APIs, downloading, etc."""

import base64  # encoding
import binascii  # encoding
import concurrent.futures  # multiprocessing/threading
import glob  # pem file lookup
import hashlib  # salt
import os  # filesystem read
import random  # salt
import re  # regexes
import time  # salt
import zlib  # encoding

import requests  # downloading
from bs4 import BeautifulSoup  # scraping
from bbarchivist import utilities  # parse filesize
from bbarchivist.bbconstants import SERVERS, TCLMASTERS  # lookup servers

try:
    from defusedxml import ElementTree  # safer XML parsing
except (ImportError, AttributeError):
    from xml.etree import ElementTree  # XML parsing

__author__ = "Thurask"
__license__ = "WTFPL v2"
__copyright__ = "2015-2018 Thurask"


def grab_pem():
    """
    Work with either local cacerts or system cacerts.
    """
    try:
        pemfile = glob.glob(os.path.join(os.getcwd(), "cacert.pem"))[0]
    except IndexError:
        return requests.certs.where()  # no local cacerts
    else:
        return os.path.abspath(pemfile)  # local cacerts


def pem_wrapper(method):
    """
    Decorator to set REQUESTS_CA_BUNDLE.

    :param method: Method to use.
    :type method: function
    """
    def wrapper(*args, **kwargs):
        """
        Set REQUESTS_CA_BUNDLE before doing function.
        """
        os.environ["REQUESTS_CA_BUNDLE"] = grab_pem()
        return method(*args, **kwargs)
    return wrapper


def try_try_again(method):
    """
    Decorator to absorb timeouts, proxy errors, and other common exceptions.

    :param method: Method to use.
    :type method: function
    """
    def wrapper(*args, **kwargs):
        """
        Try function, try it again up to five times, and leave gracefully.
        """
        tries = 5
        for _ in range(tries):
            try:
                result = method(*args, **kwargs)
            except (requests.exceptions.Timeout, requests.exceptions.ConnectionError, requests.exceptions.ProxyError):
                continue
            else:
                break
        else:
            result = None
        return result
    return wrapper


def generic_session(session=None):
    """
    Create a Requests session object on the fly, if need be.

    :param session: Requests session object, created if this is None.
    :type session: requests.Session()
    """
    sess = requests.Session() if session is None else session
    return sess


def generic_soup_parser(url, session=None):
    """
    Get a BeautifulSoup HTML parser for some URL.

    :param url: The URL to check.
    :type url: str

    :param session: Requests session object, default is created on the fly.
    :type session: requests.Session()
    """
    session = generic_session(session)
    req = session.get(url)
    soup = BeautifulSoup(req.content, "html.parser")
    return soup


@pem_wrapper
def get_length(url, session=None):
    """
    Get content-length header from some URL.

    :param url: The URL to check.
    :type url: str

    :param session: Requests session object, default is created on the fly.
    :type session: requests.Session()
    """
    session = generic_session(session)
    if url is None:
        return 0
    try:
        heads = session.head(url)
        fsize = heads.headers['content-length']
        return int(fsize)
    except requests.ConnectionError:
        return 0


@pem_wrapper
def download(url, output_directory=None, session=None):
    """
    Download file from given URL.

    :param url: URL to download from.
    :type url: str

    :param output_directory: Download folder. Default is local.
    :type output_directory: str

    :param session: Requests session object, default is created on the fly.
    :type session: requests.Session()
    """
    session = generic_session(session)
    output_directory = utilities.dirhandler(output_directory, os.getcwd())
    lfname = url.split('/')[-1]
    sname = utilities.stripper(lfname)
    fname = os.path.join(output_directory, lfname)
    download_writer(url, fname, lfname, sname, session)
    remove_empty_download(fname)


def remove_empty_download(fname):
    """
    Remove file if it's empty.

    :param fname: File path.
    :type fname: str
    """
    if os.stat(fname).st_size == 0:
        os.remove(fname)


def download_writer(url, fname, lfname, sname, session=None):
    """
    Download file and write to disk.

    :param url: URL to download from.
    :type url: str

    :param fname: File path.
    :type fname: str

    :param lfname: Long filename.
    :type lfname: str

    :param sname: Short name, for printing to screen.
    :type sname: str

    :param session: Requests session object, default is created on the fly.
    :type session: requests.Session()
    """
    with open(fname, "wb") as file:
        req = session.get(url, stream=True)
        clength = req.headers['content-length']
        fsize = utilities.fsizer(clength)
        if req.status_code == 200:  # 200 OK
            print("DOWNLOADING {0} [{1}]".format(sname, fsize))
            for chunk in req.iter_content(chunk_size=1024):
                file.write(chunk)
        else:
            print("ERROR: HTTP {0} IN {1}".format(req.status_code, lfname))


def download_bootstrap(urls, outdir=None, workers=5, session=None):
    """
    Run downloaders for each file in given URL iterable.

    :param urls: URLs to download.
    :type urls: list

    :param outdir: Download folder. Default is handled in :func:`download`.
    :type outdir: str

    :param workers: Number of worker processes. Default is 5.
    :type workers: int

    :param session: Requests session object, default is created on the fly.
    :type session: requests.Session()
    """
    workers = len(urls) if len(urls) < workers else workers
    spinman = utilities.SpinManager()
    with concurrent.futures.ThreadPoolExecutor(max_workers=workers) as xec:
        try:
            spinman.start()
            for url in urls:
                xec.submit(download, url, outdir, session)
        except (KeyboardInterrupt, SystemExit):
            xec.shutdown()
            spinman.stop()
    spinman.stop()
    utilities.spinner_clear()
    utilities.line_begin()


def download_android_tools(downloaddir=None):
    """
    Download Android SDK platform tools.

    :param downloaddir: Directory name, default is "plattools".
    :type downloaddir: str
    """
    if downloaddir is None:
        downloaddir = "plattools"
    if os.path.exists(downloaddir):
        os.removedirs(downloaddir)
    os.mkdir(downloaddir)
    platforms = ("windows", "linux", "darwin")
    baseurl = "https://dl.google.com/android/repository/platform-tools-latest"
    dlurls = ["{1}-{0}.zip".format(plat, baseurl) for plat in platforms]
    sess = generic_session()
    download_bootstrap(dlurls, outdir="plattools", session=sess)


@pem_wrapper
def getcode(url, session=None):
    """
    Return status code of given URL.

    :param url: URL to check.
    :type url: str

    :param session: Requests session object, default is created on the fly.
    :type session: requests.Session()
    """
    session = generic_session(session)
    try:
        shead = session.head(url)
        status = int(shead.status_code)
        return status
    except requests.ConnectionError:
        return 404


@pem_wrapper
def availability(url, session=None):
    """
    Check HTTP status code of given URL.
    200 or 301-308 is OK, else is not.

    :param url: URL to check.
    :type url: str

    :param session: Requests session object, default is created on the fly.
    :type session: requests.Session()
    """
    status = getcode(url, session)
    return status == 200 or 300 < status <= 308


def clean_availability(results, server):
    """
    Clean availability for autolookup script.

    :param results: Result dict.
    :type results: dict(str: str)

    :param server: Server, key for result dict.
    :type server: str
    """
    marker = "PD" if server == "p" else server.upper()
    rel = results[server.lower()]
    avail = marker if rel != "SR not in system" and rel is not None else "  "
    return rel, avail


def tcl_master():
    """
    Get a random master server.
    """
    return random.choice(TCLMASTERS)


def tcl_default_id(devid):
    """
    Get an IMEI or a serial number or something.

    :param devid: Return default if this is None.
    :type devid: str
    """
    if devid is None:
        devid = "543212345000000"
    return devid


def check_prep(curef, mode=4, fvver="AAA000", cltp=2010, cktp=2, rtd=1, chnl=2, devid=None):
    """
    Prepare variables for TCL update check.

    :param curef: PRD of the phone variant to check.
    :type curef: str

    :param mode: 4 if downloading autoloaders, 2 if downloading OTA deltas.
    :type mode: int

    :param fvver: Initial software version, must be specific if downloading OTA deltas.
    :type fvver: str

    :param cltp: 2010 to always show latest version, 10 to show actual updates. Default is 2010.
    :type cltp: int

    :param cktp: 2 if checking manually, 1 if checking automatically. Default is 2.
    :type cktp: int

    :param rtd: 2 if rooted, 1 if not. Default is 1.
    :type rtd: int

    :param chnl: 2 if checking on WiFi, 1 if checking on mobile. Default is 2.
    :type chnl: int

    :param devid: Serial number/IMEI. Default is fake, not that it matters.
    :type devid: str
    """
    devid = tcl_default_id(devid)
    geturl = "http://{0}/check.php".format(tcl_master())
    params = {"id": devid, "curef": curef, "fv": fvver, "mode": mode, "type": "Firmware", "cltp": cltp, "cktp": cktp, "rtd": rtd, "chnl": chnl}
    return geturl, params


@pem_wrapper
@try_try_again
def tcl_check(curef, session=None, mode=4, fvver="AAA000", export=False):
    """
    Check TCL server for updates.

    :param curef: PRD of the phone variant to check.
    :type curef: str

    :param session: Requests session object, default is created on the fly.
    :type session: requests.Session()

    :param mode: 4 if downloading autoloaders, 2 if downloading OTA deltas.
    :type mode: int

    :param fvver: Initial software version, must be specific if downloading OTA deltas.
    :type fvver: str

    :param export: Whether to export XML response to file. Default is False.
    :type export: bool
    """
    sess = generic_session(session)
    geturl, params = check_prep(curef, mode, fvver)
    req = sess.get(geturl, params=params)
    if req.status_code == 200:
        req.encoding = "utf-8"
        response = req.text
        if export:
            dump_tcl_xml(response)
    else:
        response = None
    return response


def parse_tcl_check(data):
    """
    Extract version and file info from TCL update server response.

    :param data: The data to parse.
    :type data: str
    """
    root = ElementTree.fromstring(data)
    tvver = root.find("VERSION").find("TV").text
    fwid = root.find("FIRMWARE").find("FW_ID").text
    fileinfo = root.find("FIRMWARE").find("FILESET").find("FILE")
    filename = fileinfo.find("FILENAME").text
    filesize = fileinfo.find("SIZE").text
    filehash = fileinfo.find("CHECKSUM").text
    return tvver, fwid, filename, filesize, filehash


def tcl_salt():
    """
    Generate salt value for TCL server tools.
    """
    millis = round(time.time() * 1000)
    tail = "{0:06d}".format(random.randint(0, 999999))
    return "{0}{1}".format(str(millis), tail)


def dump_tcl_xml(xmldata):
    """
    Write XML responses to output directory.

    :param xmldata: Response XML.
    :type xmldata: str
    """
    outfile = os.path.join(os.getcwd(), "logs", "{0}.xml".format(tcl_salt()))
    if not os.path.exists(os.path.dirname(outfile)):
        os.makedirs(os.path.dirname(outfile))
    with open(outfile, "w", encoding="utf-8") as afile:
        afile.write(xmldata)


def unpack_vdkey():
    """
    Draw the curtain back.
    """
    vdkey = b"eJwdjwEOwDAIAr8kKFr//7HhmqXp8AIIDrYAgg8byiUXrwRJRXja+d6iNxu0AhUooDCN9rd6rDLxmGIakUVWo3IGCTRWqCAt6X4jGEIUAxgN0eYWnp+LkpHQAg/PsO90ELsy0Npm/n2HbtPndFgGEV31R9OmT4O4nrddjc3Qt6nWscx7e+WRHq5UnOudtjw5skuV09pFhvmqnOEIs4ljPeel1wfLYUF4\n"
    vdk = zlib.decompress(binascii.a2b_base64(vdkey))
    return vdk.decode("utf-8")


def vkhash(curef, tvver, fwid, salt, mode=4, fvver="AAA000", cltp=2010, devid=None):
    """
    Generate hash from TCL update server variables.

    :param curef: PRD of the phone variant to check.
    :type curef: str

    :param tvver: Target software version.
    :type tvver: str

    :param fwid: Firmware ID for desired download file.
    :type fwid: str

    :param salt: Salt hash.
    :type salt: str

    :param mode: 4 if downloading autoloaders, 2 if downloading OTA deltas.
    :type mode: int

    :param fvver: Initial software version, must be specific if downloading OTA deltas.
    :type fvver: str

    :param cltp: 2010 to always show latest version, 10 to show actual updates. Default is 2010.
    :type cltp: int

    :param devid: Serial number/IMEI. Default is fake, not that it matters.
    :type devid: str
    """
    vdk = unpack_vdkey()
    devid = tcl_default_id(devid)
    query = "id={0}&salt={1}&curef={2}&fv={3}&tv={4}&type={5}&fw_id={6}&mode={7}&cltp={8}{9}".format(devid, salt, curef, fvver, tvver, "Firmware", fwid, mode, cltp, vdk)
    engine = hashlib.sha1()
    engine.update(bytes(query, "utf-8"))
    return engine.hexdigest()


def download_request_prep(curef, tvver, fwid, salt, vkh, mode=4, fvver="AAA000", cltp=2010, devid=None):
    """
    Prepare variables for download server check.

    :param curef: PRD of the phone variant to check.
    :type curef: str

    :param tvver: Target software version.
    :type tvver: str

    :param fwid: Firmware ID for desired download file.
    :type fwid: str

    :param salt: Salt hash.
    :type salt: str

    :param vkh: VDKey-based hash.
    :type vkh: str

    :param mode: 4 if downloading autoloaders, 2 if downloading OTA deltas.
    :type mode: int

    :param fvver: Initial software version, must be specific if downloading OTA deltas.
    :type fvver: str

    :param cltp: 2010 to always show latest version, 10 to show actual updates. Default is 2010.
    :type cltp: int

    :param devid: Serial number/IMEI. Default is fake, not that it matters.
    :type devid: str
    """
    devid = tcl_default_id(devid)
    posturl = "http://{0}/download_request.php".format(tcl_master())
    params = {"id": devid, "curef": curef, "fv": fvver, "mode": mode, "type": "Firmware", "tv": tvver, "fw_id": fwid, "salt": salt, "vk": vkh, "cltp": cltp}
    if mode == 4:
        params["foot"] = 1
    return posturl, params


@pem_wrapper
@try_try_again
def tcl_download_request(curef, tvver, fwid, salt, vkh, session=None, mode=4, fvver="AAA000", export=False):
    """
    Check TCL server for download URLs.

    :param curef: PRD of the phone variant to check.
    :type curef: str

    :param tvver: Target software version.
    :type tvver: str

    :param fwid: Firmware ID for desired download file.
    :type fwid: str

    :param salt: Salt hash.
    :type salt: str

    :param vkh: VDKey-based hash.
    :type vkh: str

    :param session: Requests session object, default is created on the fly.
    :type session: requests.Session()

    :param mode: 4 if downloading autoloaders, 2 if downloading OTA deltas.
    :type mode: int

    :param fvver: Initial software version, must be specific if downloading OTA deltas.
    :type fvver: str

    :param export: Whether to export XML response to file. Default is False.
    :type export: bool
    """
    sess = generic_session(session)
    posturl, params = download_request_prep(curef, tvver, fwid, salt, vkh, mode, fvver)
    req = sess.post(posturl, data=params)
    if req.status_code == 200:
        req.encoding = "utf-8"
        response = req.text
        if export:
            dump_tcl_xml(response)
    else:
        response = None
    return response


def parse_tcl_download_request(body, mode=4):
    """
    Extract file URL and encrypt slave URL from TCL update server response.

    :param data: The data to parse.
    :type data: str

    :param mode: 4 if downloading autoloaders, 2 if downloading OTA deltas.
    :type mode: int
    """
    root = ElementTree.fromstring(body)
    slavelist = root.find("SLAVE_LIST").findall("SLAVE")
    slave = random.choice(slavelist).text
    dlurl = root.find("FILE_LIST").find("FILE").find("DOWNLOAD_URL").text
    eslave = root.find("SLAVE_LIST").findall("ENCRYPT_SLAVE")
    encslave = None if mode == 2 or not eslave else random.choice(eslave).text
    return "http://{0}{1}".format(slave, dlurl), encslave


def encrypt_header_prep(address, encslave):
    """
    Prepare variables for encrypted header check.

    :param address: File URL minus host.
    :type address: str

    :param encslave: Server hosting header script.
    :type encslave: str
    """
    encs = {b"YWNjb3VudA==" : b"emhlbmdodWEuZ2Fv", b"cGFzc3dvcmQ=": b"cWFydUQ0b2s="}
    params = {base64.b64decode(key): base64.b64decode(val) for key, val in encs.items()}
    params[b"address"] = bytes(address, "utf-8")
    posturl = "http://{0}/encrypt_header.php".format(encslave)
    return posturl, params


@pem_wrapper
def encrypt_header(address, encslave, session=None):
    """
    Check encrypted header.

    :param address: File URL minus host.
    :type address: str

    :param encslave: Server hosting header script.
    :type encslave: str

    :param session: Requests session object, default is created on the fly.
    :type session: requests.Session()
    """
    sess = generic_session(session)
    posturl, params = encrypt_header_prep(address, encslave)
    req = sess.post(posturl, data=params)
    if req.status_code == 206:  # partial
        contentlength = int(req.headers["Content-Length"])
        sentinel = "HEADER FOUND" if contentlength == 4194320 else "NO HEADER FOUND"
    else:
        sentinel = None
    return sentinel


@pem_wrapper
def remote_prd_info():
    """
    Get list of remote OTA versions.
    """
    dburl = "https://tclota.birth-online.de/json_lastupdates.php"
    req = requests.get(dburl)
    reqj = req.json()
    otadict = {val["curef"]: val["last_ota"] for val in reqj.values() if val["last_ota"] is not None}
    return otadict


def cchecker_get_tags(root):
    """
    Get country and carrier from XML.

    :param root: ElementTree we're barking up.
    :type root: xml.etree.ElementTree.ElementTree
    """
    for child in root:
        if child.tag == "country":
            country = child.get("name")
        if child.tag == "carrier":
            carrier = child.get("name")
    return country, carrier

The variable country does not seem to be defined for all execution paths.

The variable carrier does not seem to be defined for all execution paths.

@pem_wrapper
def carrier_checker(mcc, mnc, session=None):
    """
    Query BlackBerry World to map a MCC and a MNC to a country and carrier.

    :param mcc: Country code.
    :type mcc: int

    :param mnc: Network code.
    :type mnc: int

    :param session: Requests session object, default is created on the fly.
    :type session: requests.Session()
    """
    session = generic_session(session)
    baseurl = "http://appworld.blackberry.com/ClientAPI/checkcarrier"
    url = "{2}?homemcc={0}&homemnc={1}&devicevendorid=-1&pin=0".format(mcc, mnc, baseurl)
    user_agent = {'User-agent': 'AppWorld/5.1.0.60'}
    req = session.get(url, headers=user_agent)
    root = ElementTree.fromstring(req.text)
    country, carrier = cchecker_get_tags(root)
    return country, carrier


def return_npc(mcc, mnc):
    """
    Format MCC and MNC into a NPC.

    :param mcc: Country code.
    :type mcc: int

    :param mnc: Network code.
    :type mnc: int
    """
    return "{0}{1}30".format(str(mcc).zfill(3), str(mnc).zfill(3))


@pem_wrapper
def carrier_query(npc, device, upgrade=False, blitz=False, forced=None, session=None):
    """
    Query BlackBerry servers, check which update is out for a carrier.

    :param npc: MCC + MNC (see `func:return_npc`)
    :type npc: int

    :param device: Hexadecimal hardware ID.
    :type device: str

    :param upgrade: Whether to use upgrade files. False by default.
    :type upgrade: bool

    :param blitz: Whether or not to create a blitz package. False by default.
    :type blitz: bool

    :param forced: Force a software release.
    :type forced: str

    :param session: Requests session object, default is created on the fly.
    :type session: requests.Session()
    """
    session = generic_session(session)
    upg = "upgrade" if upgrade else "repair"
    forced = "latest" if forced is None else forced
    url = "https://cs.sl.blackberry.com/cse/updateDetails/2.2/"
    query = '<?xml version="1.0" encoding="UTF-8"?>'
    query += '<updateDetailRequest version="2.2.1" authEchoTS="1366644680359">'
    query += "<clientProperties>"
    query += "<hardware>"
    query += "<pin>0x2FFFFFB3</pin><bsn>1128121361</bsn>"
    query += "<imei>004401139269240</imei>"
    query += "<id>0x{0}</id>".format(device)
    query += "</hardware>"
    query += "<network>"
    query += "<homeNPC>0x{0}</homeNPC>".format(npc)
    query += "<iccid>89014104255505565333</iccid>"
    query += "</network>"
    query += "<software>"
    query += "<currentLocale>en_US</currentLocale>"
    query += "<legalLocale>en_US</legalLocale>"
    query += "</software>"
    query += "</clientProperties>"
    query += "<updateDirectives>"
    query += '<allowPatching type="REDBEND">true</allowPatching>'
    query += "<upgradeMode>{0}</upgradeMode>".format(upg)
    query += "<provideDescriptions>false</provideDescriptions>"
    query += "<provideFiles>true</provideFiles>"
    query += "<queryType>NOTIFICATION_CHECK</queryType>"
    query += "</updateDirectives>"
    query += "<pollType>manual</pollType>"
    query += "<resultPackageSetCriteria>"
    query += '<softwareRelease softwareReleaseVersion="{0}" />'.format(forced)
    query += "<releaseIndependent>"
    query += '<packageType operation="include">application</packageType>'
    query += "</releaseIndependent>"
    query += "</resultPackageSetCriteria>"
    query += "</updateDetailRequest>"
    header = {"Content-Type": "text/xml;charset=UTF-8"}
    req = session.post(url, headers=header, data=query)
    return parse_carrier_xml(req.text, blitz)


def carrier_swver_get(root):
    """
    Get software release from carrier XML.

    :param root: ElementTree we're barking up.
    :type root: xml.etree.ElementTree.ElementTree
    """
    for child in root.iter("softwareReleaseMetadata"):
        swver = child.get("softwareReleaseVersion")
    return swver

The variable swver does not seem to be defined in case the for loop on line 752 is not entered. Are you sure this can never be the case?

def carrier_child_fileappend(child, files, baseurl, blitz=False):
    """
    Append bar file links to a list from a child element.

    :param child: Child element in use.
    :type child: xml.etree.ElementTree.Element

    :param files: Filelist.
    :type files: list(str)

    :param baseurl: Base URL, URL minus the filename.
    :type baseurl: str

    :param blitz: Whether or not to create a blitz package. False by default.
    :type blitz: bool
    """
    if not blitz:
        files.append(baseurl + child.get("path"))
    else:
        if child.get("type") not in ["system:radio", "system:desktop", "system:os"]:
            files.append(baseurl + child.get("path"))
    return files


def carrier_child_finder(root, files, baseurl, blitz=False):
    """
    Extract filenames, radio and OS from child elements.

    :param root: ElementTree we're barking up.
    :type root: xml.etree.ElementTree.ElementTree

    :param files: Filelist.
    :type files: list(str)

    :param baseurl: Base URL, URL minus the filename.
    :type baseurl: str

    :param blitz: Whether or not to create a blitz package. False by default.
    :type blitz: bool
    """
    osver = radver = ""
    for child in root.iter("package"):
        files = carrier_child_fileappend(child, files, baseurl, blitz)
        if child.get("type") == "system:radio":
            radver = child.get("version")
        elif child.get("type") == "system:desktop":
            osver = child.get("version")
        elif child.get("type") == "system:os":
            osver = child.get("version")
    return osver, radver, files


def parse_carrier_xml(data, blitz=False):
    """
    Parse the response to a carrier update request and return the juicy bits.

    :param data: The data to parse.
    :type data: xml

    :param blitz: Whether or not to create a blitz package. False by default.
    :type blitz: bool
    """
    root = ElementTree.fromstring(data)
    sw_exists = root.find('./data/content/softwareReleaseMetadata')
    swver = "N/A" if sw_exists is None else ""
    if sw_exists is not None:
        swver = carrier_swver_get(root)
    files = []
    package_exists = root.find('./data/content/fileSets/fileSet')
    osver = radver = ""
    if package_exists is not None:
        baseurl = "{0}/".format(package_exists.get("url"))
        osver, radver, files = carrier_child_finder(root, files, baseurl, blitz)
    return(swver, osver, radver, files)


@pem_wrapper
def sr_lookup(osver, server, session=None):
    """
    Software release lookup, with choice of server.
    :data:`bbarchivist.bbconstants.SERVERLIST` for server list.

    :param osver: OS version to lookup, 10.x.y.zzzz.
    :type osver: str

    :param server: Server to use.
    :type server: str

    :param session: Requests session object, default is created on the fly.
    :type session: requests.Session()
    """
    query = '<?xml version="1.0" encoding="UTF-8"?>'
    query += '<srVersionLookupRequest version="2.0.0"'
    query += ' authEchoTS="1366644680359">'
    query += '<clientProperties><hardware>'
    query += '<pin>0x2FFFFFB3</pin><bsn>1140011878</bsn>'
    query += '<imei>004402242176786</imei><id>0x8D00240A</id>'
    query += '<isBootROMSecure>true</isBootROMSecure>'
    query += '</hardware>'
    query += '<network>'
    query += '<vendorId>0x0</vendorId><homeNPC>0x60</homeNPC>'
    query += '<currentNPC>0x60</currentNPC><ecid>0x1</ecid>'
    query += '</network>'
    query += '<software><currentLocale>en_US</currentLocale>'
    query += '<legalLocale>en_US</legalLocale>'
    query += '<osVersion>{0}</osVersion>'.format(osver)
    query += '<omadmEnabled>false</omadmEnabled>'
    query += '</software></clientProperties>'
    query += '</srVersionLookupRequest>'
    reqtext = sr_lookup_poster(query, server, session)
    packtext = sr_lookup_xmlparser(reqtext)
    return packtext


def sr_lookup_poster(query, server, session=None):
    """
    Post the XML payload for a software release lookup.

    :param query: XML payload.
    :type query: str

    :param server: Server to use.
    :type server: str

    :param session: Requests session object, default is created on the fly.
    :type session: requests.Session()
    """
    session = generic_session(session)
    header = {"Content-Type": "text/xml;charset=UTF-8"}
    try:
        req = session.post(server, headers=header, data=query, timeout=1)
    except (requests.exceptions.Timeout, requests.exceptions.ConnectionError):
        reqtext = "SR not in system"
    else:
        reqtext = req.text
    return reqtext


def sr_lookup_xmlparser(reqtext):
    """
    Take the text of a software lookup request response and parse it as XML.

    :param reqtext: Response text, hopefully XML formatted.
    :type reqtext: str
    """
    try:
        root = ElementTree.fromstring(reqtext)
    except ElementTree.ParseError:
        packtext = "SR not in system"
    else:
        packtext = sr_lookup_extractor(root)
    return packtext


def sr_lookup_extractor(root):
    """
    Take an ElementTree and extract a software release from it.

    :param root: ElementTree we're barking up.
    :type root: xml.etree.ElementTree.ElementTree
    """
    reg = re.compile(r"(\d{1,4}\.)(\d{1,4}\.)(\d{1,4}\.)(\d{1,4})")
    packages = root.findall('./data/content/')
    for package in packages:
        if package.text is not None:
            match = reg.match(package.text)
            packtext = package.text if match else "SR not in system"
            return packtext


def sr_lookup_bootstrap(osv, session=None, no2=False):
    """
    Run lookups for each server for given OS.

    :param osv: OS to check.
    :type osv: str

    :param session: Requests session object, default is created on the fly.
    :type session: requests.Session()

    :param no2: Whether to skip Alpha2/Beta2 servers. Default is false.
    :type no2: bool
    """
    with concurrent.futures.ThreadPoolExecutor(max_workers=5) as xec:
        try:
            results = {
                "p": None,
                "a1": None,
                "a2": None,
                "b1": None,
                "b2": None
            }
            if no2:
                del results["a2"]
                del results["b2"]
            for key in results:
                results[key] = xec.submit(sr_lookup, osv, SERVERS[key], session).result()
            return results
        except KeyboardInterrupt:
            xec.shutdown(wait=False)


@pem_wrapper
def available_bundle_lookup(mcc, mnc, device, session=None):
    """
    Check which software releases were ever released for a carrier.

    :param mcc: Country code.
    :type mcc: int

    :param mnc: Network code.
    :type mnc: int

    :param device: Hexadecimal hardware ID.
    :type device: str

    :param session: Requests session object, default is created on the fly.
    :type session: requests.Session()
    """
    session = generic_session(session)
    server = "https://cs.sl.blackberry.com/cse/availableBundles/1.0.0/"
    npc = return_npc(mcc, mnc)
    query = '<?xml version="1.0" encoding="UTF-8"?>'
    query += '<availableBundlesRequest version="1.0.0" '
    query += 'authEchoTS="1366644680359">'
    query += '<deviceId><pin>0x2FFFFFB3</pin></deviceId>'
    query += '<clientProperties><hardware><id>0x{0}</id>'.format(device)
    query += '<isBootROMSecure>true</isBootROMSecure></hardware>'
    query += '<network><vendorId>0x0</vendorId><homeNPC>0x{0}</homeNPC>'.format(npc)
    query += '<currentNPC>0x{0}</currentNPC></network><software>'.format(npc)
    query += '<currentLocale>en_US</currentLocale>'
    query += '<legalLocale>en_US</legalLocale>'
    query += '<osVersion>10.0.0.0</osVersion>'
    query += '<radioVersion>10.0.0.0</radioVersion></software>'
    query += '</clientProperties><updateDirectives><bundleVersionFilter>'
    query += '</bundleVersionFilter></updateDirectives>'
    query += '</availableBundlesRequest>'
    header = {"Content-Type": "text/xml;charset=UTF-8"}
    req = session.post(server, headers=header, data=query)
    root = ElementTree.fromstring(req.text)
    package = root.find('./data/content')
    bundlelist = [child.attrib["version"] for child in package]
    return bundlelist


@pem_wrapper
def ptcrb_scraper(ptcrbid, session=None):
    """
    Get the PTCRB results for a given device.

    :param ptcrbid: Numerical ID from PTCRB (end of URL).
    :type ptcrbid: str

    :param session: Requests session object, default is created on the fly.
    :type session: requests.Session()
    """
    baseurl = "https://www.ptcrb.com/certified-devices/device-details/?model={0}".format(ptcrbid)
    sess = generic_session(session)
    useragent = "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/61.0.3163.79 Safari/537.36"
    sess.headers.update({"User-agent": useragent})
    soup = generic_soup_parser(baseurl, sess)
    certtable = soup.find_all("table")[1]
    tds = certtable.find_all("td")[1::2]  # every other
    prelimlist = [tdx.text for tdx in tds]
    cleanlist = [ptcrb_item_cleaner(item.strip()) for item in prelimlist]
    return cleanlist


def space_pad(instring, minlength):
    """
    Pad a string with spaces until it's the minimum length.

    :param instring: String to pad.
    :type instring: str

    :param minlength: Pad while len(instring) < minlength.
    :type minlength: int
    """
    while len(instring) < minlength:
        instring += " "
    return instring


def ptcrb_cleaner_multios(item):
    """
    Discard multiple entries for "OS".

    :param item: The item to clean.
    :type item: str
    """
    if item.count("OS") > 1:
        templist = item.split("OS")
        templist[0] = "OS"
        item = "".join([templist[0], templist[1]])
    return item


def ptcrb_cleaner_spaces(item):
    """
    Pad item with spaces to the right length.

    :param item: The item to clean.
    :type item: str
    """
    spaclist = item.split(" ")
    if len(spaclist) > 1:
        spaclist[1] = space_pad(spaclist[1], 11)
    if len(spaclist) > 3:
        spaclist[3] = space_pad(spaclist[3], 11)
    item = " ".join(spaclist)
    return item


def ptcrb_item_cleaner(item):
    """
    Cleanup poorly formatted PTCRB entries written by an intern.

    :param item: The item to clean.
    :type item: str
    """
    item = item.replace("<td>", "")
    item = item.replace("</td>", "")
    item = item.replace("\n", "")
    item = item.replace("SW: OS", "OS")
    item = item.replace("Software Version: OS", "OS")
    item = item.replace(" (SR", ", SR")
    item = re.sub(r"\s?\((.*)$", "", item)
    item = re.sub(r"\sSV.*$", "", item)
    item = item.replace(")", "")
    item = item.replace(". ", ".")
    item = item.replace(";", "")
    item = item.replace("version", "Version")
    item = item.replace("Verison", "Version")
    item = ptcrb_cleaner_multios(item)
    item = item.replace("SR10", "SR 10")
    item = item.replace("SR", "SW Release")
    item = item.replace(" Version:", ":")
    item = item.replace("Version ", " ")
    item = item.replace(":1", ": 1")
    item = item.replace(", ", " ")
    item = item.replace(",", " ")
    item = item.replace("Software", "SW")
    item = item.replace("  ", " ")
    item = item.replace("OS ", "OS: ")
    item = item.replace("Radio ", "Radio: ")
    item = item.replace("Release ", "Release: ")
    item = ptcrb_cleaner_spaces(item)
    item = item.strip()
    item = item.replace("\r", "")
    if item.startswith("10"):
        item = "OS: {0}".format(item)
    item = item.replace(":    ", ": ")
    item = item.replace(":   ", ": ")
    return item


@pem_wrapper
def kernel_scraper(utils=False, session=None):
    """
    Scrape BlackBerry's GitHub kernel repo for available branches.

    :param utils: Check android-utils repo instead of android-linux-kernel. Default is False.
    :type utils: bool

    :param session: Requests session object, default is created on the fly.
    :type session: requests.Session()
    """
    repo = "android-utils" if utils else "android-linux-kernel"
    kernlist = []
    sess = generic_session(session)
    for page in range(1, 10):
        url = "https://github.com/blackberry/{0}/branches/all?page={1}".format(repo, page)
        soup = generic_soup_parser(url, sess)
        if soup.find("div", {"class": "no-results-message"}):
            break
        else:
            text = soup.get_text()
            kernlist.extend(re.findall(r"msm[0-9]{4}\/[A-Z0-9]{6}", text, re.IGNORECASE))
    return kernlist


def root_generator(folder, build, variant="common"):
    """
    Generate roots for the SHAxxx hash lookup URLs.

    :param folder: Dictionary of variant: loader name pairs.
    :type folder: dict(str: str)

    :param build: Build to check, 3 letters + 3 numbers.
    :type build: str

    :param variant: Autoloader variant. Default is "common".
    :type variant: str
    """
    #Priv specific
    privx = "bbfoundation/hashfiles_priv/{0}".format(folder[variant])
    #DTEK50 specific
    dtek50x = "bbSupport/DTEK50" if build[:3] == "AAF" else "bbfoundation/hashfiles_priv/dtek50"
    #DTEK60 specific
    dtek60x = dtek50x  # still uses dtek50 folder, for some reason
    #Pack it up
    roots = {"Priv": privx, "DTEK50": dtek50x, "DTEK60": dtek60x}
    return roots


def make_droid_skeleton_bbm(method, build, device, variant="common"):
    """
    Make an Android autoloader/hash URL, on the BB Mobile site.

    :param method: None for regular OS links, "sha256/512" for SHA256 or 512 hash.
    :type method: str

    :param build: Build to check, 3 letters + 3 numbers.
    :type build: str

    :param device: Device to check.
    :type device: str

    :param variant: Autoloader variant. Default is "common".
    :type variant: str
    """
    devices = {"KEYone": "qc8953", "Motion": "qc8953"}
    base = "bbry_{2}_autoloader_user-{0}-{1}".format(variant, build.upper(), devices[device])
    if method is None:
        skel = "http://54.247.87.13/softwareupgrade/BBM/{0}.zip".format(base)
    else:
        skel = "http://54.247.87.13/softwareupgrade/BBM/{0}.{1}sum".format(base, method.lower())
    return skel


def make_droid_skeleton_og(method, build, device, variant="common"):
    """
    Make an Android autoloader/hash URL, on the original site.

    :param method: None for regular OS links, "sha256/512" for SHA256 or 512 hash.
    :type method: str

    :param build: Build to check, 3 letters + 3 numbers.
    :type build: str

    :param device: Device to check.
    :type device: str

    :param variant: Autoloader variant. Default is "common".
    :type variant: str
    """
    folder = {"vzw-vzw": "verizon", "na-att": "att", "na-tmo": "tmo", "common": "default"}
    devices = {"Priv": "qc8992", "DTEK50": "qc8952_64_sfi", "DTEK60": "qc8996"}
    roots = root_generator(folder, build, variant)
    base = "bbry_{2}_autoloader_user-{0}-{1}".format(variant, build.upper(), devices[device])
    if method is None:
        baseurl = "https://bbapps.download.blackberry.com/Priv"
        skel = "{1}/{0}.zip".format(base, baseurl)
    else:
        baseurl = "https://ca.blackberry.com/content/dam"
        skel = "{3}/{1}/{0}.{2}sum".format(base, roots[device], method.lower(), baseurl)
    return skel


def make_droid_skeleton(method, build, device, variant="common"):
    """
    Make an Android autoloader/hash URL.

    :param method: None for regular OS links, "sha256/512" for SHA256 or 512 hash.
    :type method: str

    :param build: Build to check, 3 letters + 3 numbers.
    :type build: str

    :param device: Device to check.
    :type device: str

    :param variant: Autoloader variant. Default is "common".
    :type variant: str
    """
    # No Aurora
    oglist = ("Priv", "DTEK50", "DTEK60")  # BlackBerry
    bbmlist = ("KEYone", "Motion")   # BB Mobile
    if device in oglist:
        skel = make_droid_skeleton_og(method, build, device, variant)
    elif device in bbmlist:
        skel = make_droid_skeleton_bbm(method, build, device, variant)
    return skel

The variable skel does not seem to be defined for all execution paths.

def bulk_droid_skeletons(devs, build, method=None):
    """
    Prepare list of Android autoloader/hash URLs.

    :param devs: List of devices.
    :type devs: list(str)

    :param build: Build to check, 3 letters + 3 numbers.
    :type build: str

    :param method: None for regular OS links, "sha256/512" for SHA256 or 512 hash.
    :type method: str
    """
    carrier_variants = {
        "Priv": ("common", "vzw-vzw", "na-tmo", "na-att"),
        "KEYone": ("common", "usa-sprint", "global-att", "china-china")
    }
    common_variants = ("common", )  # for single-variant devices
    carrier_devices = ("Priv", )  # add KEYone when verified
    skels = []
    for dev in devs:
        varlist = carrier_variants[dev] if dev in carrier_devices else common_variants
        for var in varlist:
            skel = make_droid_skeleton(method, build, dev, var)
            skels.append(skel)
    return skels


def prepare_droid_list(device):
    """
    Convert single devices to a list, if necessary.

    :param device: Device to check.
    :type device: str
    """
    if isinstance(device, list):
        devs = device
    else:
        devs = [device]
    return devs


def droid_scanner(build, device, method=None, session=None):
    """
    Check for Android autoloaders on BlackBerry's site.

    :param build: Build to check, 3 letters + 3 numbers.
    :type build: str

    :param device: Device to check.
    :type device: str

    :param method: None for regular OS links, "sha256/512" for SHA256 or 512 hash.
    :type method: str

    :param session: Requests session object, default is created on the fly.
    :type session: requests.Session()
    """
    devs = prepare_droid_list(device)
    skels = bulk_droid_skeletons(devs, build, method)
    with concurrent.futures.ThreadPoolExecutor(max_workers=len(skels)) as xec:
        results = droid_scanner_worker(xec, skels, session)
    return results if results else None


def droid_scanner_worker(xec, skels, session=None):
    """
    Worker to check for Android autoloaders.

    :param xec: ThreadPoolExecutor instance.
    :type xec: concurrent.futures.ThreadPoolExecutor

    :param skels: List of skeleton formats.
    :type skels: list(str)

    :param session: Requests session object, default is created on the fly.
    :type session: requests.Session()
    """
    results = []
    for skel in skels:
        avail = xec.submit(availability, skel, session)
        if avail.result():
            results.append(skel)
    return results


def chunker(iterable, inc):
    """
    Convert an iterable into a list of inc sized lists.

    :param iterable: Iterable to chunk.
    :type iterable: list/tuple/string

    :param inc: Increment; how big each chunk is.
    :type inc: int
    """
    chunks = [iterable[x:x+inc] for x in range(0, len(iterable), inc)]
    return chunks


def unicode_filter(intext):
    """
    Remove Unicode crap.

    :param intext: Text to filter.
    :type intext: str
    """
    return intext.replace("\u2013", "").strip()


def table_header_filter(ptag):
    """
    Validate p tag, to see if it's relevant.

    :param ptag: P tag.
    :type ptag: bs4.element.Tag
    """
    valid = ptag.find("b") and "BlackBerry" in ptag.text and not "experts" in ptag.text
    return valid


def table_headers(pees):
    """
    Generate table headers from list of p tags.

    :param pees: List of p tags.
    :type pees: list(bs4.element.Tag)
    """
    bolds = [x.text for x in pees if table_header_filter(x)]
    return bolds


@pem_wrapper
def loader_page_scraper(session=None):
    """
    Return scraped autoloader pages.

    :param session: Requests session object, default is created on the fly.
    :type session: requests.Session()
    """
    session = generic_session(session)
    loader_page_scraper_og(session)
    loader_page_scraper_bbm(session)


def loader_page_scraper_og(session=None):
    """
    Return scraped autoloader page, original site.

    :param session: Requests session object, default is created on the fly.
    :type session: requests.Session()
    """
    url = "https://ca.blackberry.com/support/smartphones/Android-OS-Reload.html"
    soup = generic_soup_parser(url, session)
    tables = soup.find_all("table")
    headers = table_headers(soup.find_all("p"))
    for idx, table in enumerate(tables):
        loader_page_chunker_og(idx, table, headers)


def loader_page_scraper_bbm(session=None):
    """
    Return scraped autoloader page, new site.

    :param session: Requests session object, default is created on the fly.
    :type session: requests.Session()
    """
    url = "https://www.blackberrymobile.com/support/reload-software/"
    soup = generic_soup_parser(url, session)
    ulls = soup.find_all("ul", {"class": re.compile("list-two special-.")})[1:]
    print("~~~BlackBerry KEYone~~~")
    for ull in ulls:
        loader_page_chunker_bbm(ull)


def loader_page_chunker_og(idx, table, headers):
    """
    Given a loader page table, chunk it into lists of table cells.

    :param idx: Index of enumerating tables.
    :type idx: int

    :param table: HTML table tag.
    :type table: bs4.element.Tag

    :param headers: List of table headers.
    :type headers: list(str)
    """
    print("~~~{0}~~~".format(headers[idx]))
    chunks = chunker(table.find_all("td"), 4)
    for chunk in chunks:
        loader_page_printer(chunk)
    print(" ")


def loader_page_chunker_bbm(ull):
    """
    Given a loader page list, chunk it into lists of list items.

    :param ull: HTML unordered list tag.
    :type ull: bs4.element.Tag
    """
    chunks = chunker(ull.find_all("li"), 3)
    for chunk in chunks:
        loader_page_printer(chunk)


def loader_page_printer(chunk):
    """
    Print individual cell texts given a list of table cells.

    :param chunk: List of td tags.
    :type chunk: list(bs4.element.Tag)
    """
    key = unicode_filter(chunk[0].text)
    ver = unicode_filter(chunk[1].text)
    link = unicode_filter(chunk[2].find("a")["href"])
    print("{0}\n    {1}: {2}".format(key, ver, link))


@pem_wrapper
def base_metadata(url, session=None):
    """
    Get BBNDK metadata, base function.

    :param url: URL to check.
    :type url: str

    :param session: Requests session object, default is created on the fly.
    :type session: requests.Session()
    """
    session = generic_session(session)
    req = session.get(url)
    data = req.content
    entries = data.split(b"\n")
    metadata = [entry.split(b",")[1].decode("utf-8") for entry in entries if entry]
    return metadata


def base_metadata_url(alternate=None):
    """
    Return metadata URL.

    :param alternate: If the URL is for the simulator metadata. Default is False.
    :type alternate: str
    """
    baseurl = "http://downloads.blackberry.com/upr/developers/update/bbndk"
    tail = "{0}/{0}_metadata".format(alternate) if alternate is not None else "metadata"
    return "{0}/{1}".format(baseurl, tail)


def ndk_metadata(session=None):
    """
    Get BBNDK target metadata.

    :param session: Requests session object, default is created on the fly.
    :type session: requests.Session()
    """
    ndkurl = base_metadata_url()
    data = base_metadata(ndkurl, session)
    metadata = [entry for entry in data if entry.startswith(("10.0", "10.1", "10.2"))]
    return metadata


def sim_metadata(session=None):
    """
    Get BBNDK simulator metadata.

    :param session: Requests session object, default is created on the fly.
    :type session: requests.Session()
    """
    simurl = base_metadata_url("simulator")
    metadata = base_metadata(simurl, session)
    return metadata


def runtime_metadata(session=None):
    """
    Get BBNDK runtime metadata.

    :param session: Requests session object, default is created on the fly.
    :type session: requests.Session()
    """
    rturl = base_metadata_url("runtime")
    metadata = base_metadata(rturl, session)
    return metadata


def series_generator(osversion):
    """
    Generate series/branch name from OS version.

    :param osversion: OS version.
    :type osversion: str
    """
    splits = osversion.split(".")
    return "BB{0}_{1}_{2}".format(*splits[0:3])


@pem_wrapper
def devalpha_urls(osversion, skel, session=None):
    """
    Check individual Dev Alpha autoloader URLs.

    :param osversion: OS version.
    :type osversion: str

    :param skel: Individual skeleton format to try.
    :type skel: str

    :param session: Requests session object, default is created on the fly.
    :type session: requests.Session()
    """
    session = generic_session(session)
    baseurl = "http://downloads.blackberry.com/upr/developers/downloads"
    url = "{2}/{0}{1}.exe".format(skel, osversion, baseurl)
    req = session.head(url)
    if req.status_code == 200:
        finals = (url, req.headers["content-length"])
    else:
        finals = ()
    return finals


def devalpha_urls_serieshandler(osversion, skeletons):
    """
    Process list of candidate Dev Alpha autoloader URLs.

    :param osversion: OS version.
    :type osversion: str

    :param skeletons: List of skeleton formats to try.
    :type skeletons: list
    """
    skels = skeletons
    for idx, skel in enumerate(skeletons):
        if "<SERIES>" in skel:
            skels[idx] = skel.replace("<SERIES>", series_generator(osversion))
    return skels


def devalpha_urls_bulk(osversion, skeletons, xec, session=None):
    """
    Construct list of valid Dev Alpha autoloader URLs.

    :param osversion: OS version.
    :type osversion: str

    :param skeletons: List of skeleton formats to try.
    :type skeletons: list

    :param xec: ThreadPoolExecutor instance.
    :type xec: concurrent.futures.ThreadPoolExecutor

    :param session: Requests session object, default is created on the fly.
    :type session: requests.Session()
    """
    finals = {}
    skels = devalpha_urls_serieshandler(osversion, skeletons)
    for skel in skels:
        final = xec.submit(devalpha_urls, osversion, skel, session).result()
        if final:
            finals[final[0]] = final[1]
    return finals


def devalpha_urls_bootstrap(osversion, skeletons, session=None):
    """
    Get list of valid Dev Alpha autoloader URLs.

    :param osversion: OS version.
    :type osversion: str

    :param skeletons: List of skeleton formats to try.
    :type skeletons: list

    :param session: Requests session object, default is created on the fly.
    :type session: requests.Session()
    """
    with concurrent.futures.ThreadPoolExecutor(max_workers=5) as xec:
        try:
            return devalpha_urls_bulk(osversion, skeletons, xec, session)
        except KeyboardInterrupt:
            xec.shutdown(wait=False)


def dev_dupe_dicter(finals):
    """
    Prepare dictionary to clean duplicate autoloaders.

    :param finals: Dict of URL:content-length pairs.
    :type finals: dict(str: str)
    """
    revo = {}
    for key, val in finals.items():
        revo.setdefault(val, set()).add(key)
    return revo


def dev_dupe_remover(finals, dupelist):
    """
    Filter dictionary of autoloader entries.

    :param finals: Dict of URL:content-length pairs.
    :type finals: dict(str: str)

    :param dupelist: List of duplicate URLs.
    :type duplist: list(str)
    """
    for dupe in dupelist:
        for entry in dupe:
            if "DevAlpha" in entry:
                del finals[entry]
    return finals


def dev_dupe_cleaner(finals):
    """
    Clean duplicate autoloader entries.

    :param finals: Dict of URL:content-length pairs.
    :type finals: dict(str: str)
    """
    revo = dev_dupe_dicter(finals)
    dupelist = [val for key, val in revo.items() if len(val) > 1]
    finals = dev_dupe_remover(finals, dupelist)
    return finals