diff --git a/tclcheck.py b/tclcheck.py
index 5405049..a1b4a52 100755
--- a/tclcheck.py
+++ b/tclcheck.py
@@ -6,14 +6,14 @@
 """Checks for the latest FULL or OTA updates for specified PRD number."""
 
 import os
-import random
 import sys
 
 from tcllib import argparser
 from tcllib.devices import Device
 from tcllib.dumpmgr import write_info_if_dumps_found
-from tcllib.requests import RequestRunner, CheckRequest, DownloadRequest, \
-        ChecksumRequest, EncryptHeaderRequest, ServerSelector
+from tcllib.requests import (CheckRequest, ChecksumRequest, DownloadRequest,
+                             EncryptHeaderRequest, RequestRunner,
+                             ServerSelector)
 
 
 dpdesc = """
@@ -33,6 +33,7 @@ args = dp.parse_args(sys.argv[1:])
 dev = Device(args.prd[0], args.fvver)
 dev.imei = "3531510"
 
+
 def sel_mode(txtmode, autoval, rawval):
     """Handle custom mode."""
     if rawval:
@@ -43,6 +44,7 @@ def sel_mode(txtmode, autoval, rawval):
         return dev.MODE_STATES["OTA"]
     return dev.MODE_STATES["FULL"]
 
+
 def sel_cltp(txtmode, autoval, rawval):
     """Handle custom CLTP."""
     if rawval:
@@ -53,6 +55,7 @@ def sel_cltp(txtmode, autoval, rawval):
         return dev.CLTP_STATES["DESKTOP"]
     return dev.CLTP_STATES["MOBILE"]
 
+
 if args.imei:
     print("Use specified IMEI: {}".format(args.imei))
     dev.imei = args.imei
diff --git a/tclcheck_allfull.py b/tclcheck_allfull.py
index 1b76ae0..41ff399 100644
--- a/tclcheck_allfull.py
+++ b/tclcheck_allfull.py
@@ -10,7 +10,7 @@ import sys
 from tcllib import ansi, argparser, devlist
 from tcllib.devices import DesktopDevice
 from tcllib.dumpmgr import write_info_if_dumps_found
-from tcllib.requests import RequestRunner, CheckRequest, ServerVoteSelector
+from tcllib.requests import CheckRequest, RequestRunner, ServerVoteSelector
 
 
 dev = DesktopDevice()
diff --git a/tclcheck_allota.py b/tclcheck_allota.py
index 044726a..26a1b47 100644
--- a/tclcheck_allota.py
+++ b/tclcheck_allota.py
@@ -10,7 +10,7 @@ import sys
 from tcllib import ansi, argparser, devlist
 from tcllib.devices import MobileDevice
 from tcllib.dumpmgr import write_info_if_dumps_found
-from tcllib.requests import RequestRunner, CheckRequest, ServerVoteSelector
+from tcllib.requests import CheckRequest, RequestRunner, ServerVoteSelector
 
 
 dev = MobileDevice()
diff --git a/tclcheck_findprd.py b/tclcheck_findprd.py
index 3d8a168..d4ee95b 100755
--- a/tclcheck_findprd.py
+++ b/tclcheck_findprd.py
@@ -11,7 +11,7 @@ import sys
 from tcllib import ansi, argparser, devlist
 from tcllib.devices import DesktopDevice
 from tcllib.dumpmgr import write_info_if_dumps_found
-from tcllib.requests import RequestRunner, CheckRequest, ServerVoteSelector
+from tcllib.requests import CheckRequest, RequestRunner, ServerVoteSelector
 
 
 dpdesc = """
diff --git a/tclcheck_findprd2.py b/tclcheck_findprd2.py
index a166ef9..2fa05cc 100644
--- a/tclcheck_findprd2.py
+++ b/tclcheck_findprd2.py
@@ -10,7 +10,7 @@ import sys
 from tcllib import ansi, argparser, devlist
 from tcllib.devices import DesktopDevice
 from tcllib.dumpmgr import write_info_if_dumps_found
-from tcllib.requests import RequestRunner, CheckRequest, ServerVoteSelector
+from tcllib.requests import CheckRequest, RequestRunner, ServerVoteSelector
 
 
 # Variants to scan for
diff --git a/tclcheck_findver.py b/tclcheck_findver.py
index 808e9ca..9f06b6f 100755
--- a/tclcheck_findver.py
+++ b/tclcheck_findver.py
@@ -7,10 +7,10 @@
 
 import sys
 
-from tcllib import ansi, argparser, devlist
+from tcllib import ansi, argparser
 from tcllib.devices import MobileDevice
 from tcllib.dumpmgr import write_info_if_dumps_found
-from tcllib.requests import RequestRunner, CheckRequest, ServerVoteSelector
+from tcllib.requests import CheckRequest, RequestRunner, ServerVoteSelector
 
 
 dpdesc = """
diff --git a/tclcheck_gapfill.py b/tclcheck_gapfill.py
index 9e11604..9972c02 100644
--- a/tclcheck_gapfill.py
+++ b/tclcheck_gapfill.py
@@ -6,12 +6,12 @@
 """Query existence of missing OTAs."""
 
 import json
+
 import requests
 
-from tcllib import ansi
 from tcllib.devices import MobileDevice
 from tcllib.dumpmgr import write_info_if_dumps_found
-from tcllib.requests import RequestRunner, CheckRequest, ServerVoteSelector
+from tcllib.requests import CheckRequest, RequestRunner, ServerVoteSelector
 
 
 # 1. Fetch list of missing OTAs (e.g. from ancient versions to current)
diff --git a/tclchksum.py b/tclchksum.py
index 18a3d0c..755fad6 100644
--- a/tclchksum.py
+++ b/tclchksum.py
@@ -8,7 +8,7 @@
 import sys
 
 from tcllib import argparser
-from tcllib.requests import RequestRunner, ChecksumRequest, ServerSelector
+from tcllib.requests import ChecksumRequest, RequestRunner, ServerSelector
 
 encslaves = [
     "54.238.56.196",
diff --git a/tcldown.py b/tcldown.py
index 73fb3dd..12e7d30 100644
--- a/tcldown.py
+++ b/tcldown.py
@@ -11,8 +11,8 @@ import sys
 from tcllib import argparser
 from tcllib.devices import DesktopDevice
 from tcllib.dumpmgr import write_info_if_dumps_found
-from tcllib.requests import RequestRunner, CheckRequest, DownloadRequest, \
-        ChecksumRequest, EncryptHeaderRequest, ServerSelector
+from tcllib.requests import (DownloadRequest, EncryptHeaderRequest,
+                             RequestRunner, ServerSelector)
 
 
 dpdesc = """
@@ -31,6 +31,7 @@ args = dp.parse_args(sys.argv[1:])
 
 dev = DesktopDevice()
 
+
 def sel_mode(defaultmode, rawval):
     """Handle custom mode."""
     if rawval:
diff --git a/tcllib/__init__.py b/tcllib/__init__.py
index 9d6eeee..b940875 100644
--- a/tcllib/__init__.py
+++ b/tcllib/__init__.py
@@ -1,3 +1,4 @@
+#!/usr/bin/env python3
 # -*- coding: utf-8 -*-
 
 """Library for TCL API work and related functions."""
diff --git a/tcllib/devices.py b/tcllib/devices.py
index bcd8b97..f55444b 100644
--- a/tcllib/devices.py
+++ b/tcllib/devices.py
@@ -1,3 +1,4 @@
+#!/usr/bin/env python3
 # -*- coding: utf-8 -*-
 
 """Pseudo-devices for desktop/mobile requests"""
@@ -27,7 +28,7 @@ class Device():
         self.chnl = self.CHNL_STATES["WIFI"]
         self.cktp = self.CKTP_STATES["MANUAL"]
         self.ckot = self.CKOT_STATES["ALL"]
-        self.ua = "tcl"
+        self.uagent = "tcl"
 
     def is_rooted(self):
         """Get RTD as boolean."""
@@ -71,7 +72,7 @@ class MobileDevice(Device):
         self.imei = "3531510"
         self.set_cltp("MOBILE")
         self.set_mode("OTA")
-        self.ua = "com.tcl.fota/5.1.0.2.0029.0, Android"
+        self.uagent = "com.tcl.fota/5.1.0.2.0029.0, Android"
 
 
 class DesktopDevice(Device):
diff --git a/tcllib/dumpmgr.py b/tcllib/dumpmgr.py
index e6bf993..182ede8 100644
--- a/tcllib/dumpmgr.py
+++ b/tcllib/dumpmgr.py
@@ -21,6 +21,7 @@ def get_timestamp_random():
     tail = "{:06d}".format(random.randint(0, 999999))
     return "{}_{}".format(str(millis), tail)
 
+
 def write_info_if_dumps_found():
     """Notify user to upload dumps if present."""
     # To disable this info, uncomment the following line.
@@ -31,6 +32,7 @@ def write_info_if_dumps_found():
         print("{}There are {} logs collected in the logs/ directory.{} Please consider uploading".format(ansi.YELLOW, len(files), ansi.RESET))
         print("them to https://tclota.birth-online.de/ by running {}./upload_logs.py{}.".format(ansi.CYAN, ansi.RESET))
 
+
 class DumpMgr:
     """A class for XML dump management."""
 
diff --git a/tcllib/requests/__init__.py b/tcllib/requests/__init__.py
index 7872868..afe17ce 100644
--- a/tcllib/requests/__init__.py
+++ b/tcllib/requests/__init__.py
@@ -1,8 +1,11 @@
+#!/usr/bin/env python3
 # -*- coding: utf-8 -*-
 
+"""Library for generic TCL API requests."""
+
 from .checkrequest import CheckRequest
-from .downloadrequest import DownloadRequest
 from .checksumrequest import ChecksumRequest
+from .downloadrequest import DownloadRequest
 from .encryptheaderrequest import EncryptHeaderRequest
 from .runner import *
 from .serverselector import *
diff --git a/tcllib/requests/checkrequest.py b/tcllib/requests/checkrequest.py
index 353b495..db5d88b 100644
--- a/tcllib/requests/checkrequest.py
+++ b/tcllib/requests/checkrequest.py
@@ -1,21 +1,31 @@
+#!/usr/bin/env python3
 # -*- coding: utf-8 -*-
 
+"""Generic update check request."""
+
 from collections import OrderedDict
+
 from .. import devices
 from .tclrequest import TclRequest
 from .tclresult import CheckResult
 
+
 class CheckRequest(TclRequest):
+    """Generic update check request."""
+
     def __init__(self, device: devices.Device):
+        """Populate variables.."""
         super().__init__()
         self.uri = "/check.php"
         self.method = "GET"
         self.device = device
-    
+
     def get_headers(self):
-        return {"User-Agent": self.device.ua}
+        """Return request headers."""
+        return {"User-Agent": self.device.uagent}
 
     def get_params(self):
+        """Return request parameters."""
         params = OrderedDict()
         params["id"] = self.device.imei
         params["curef"] = self.device.curef
@@ -31,6 +41,7 @@ class CheckRequest(TclRequest):
         return params
 
     def is_done(self, http_status: int, contents: str) -> bool:
+        """Handle request result."""
         ok_states = {
             204: "No update available.",
             404: "No data for requested CUREF/FV combination.",
@@ -47,7 +58,7 @@ class CheckRequest(TclRequest):
         elif http_status not in [500, 502, 503]:
             # Errors OTHER than 500, 502 or 503 are probably
             # errors where we don't need to retry
-            self.error ="HTTP {}.".format(http_status)
+            self.error = "HTTP {}.".format(http_status)
             self.success = False
             return True
         return False
diff --git a/tcllib/requests/checksumrequest.py b/tcllib/requests/checksumrequest.py
index 2ec2f89..e2a8d77 100644
--- a/tcllib/requests/checksumrequest.py
+++ b/tcllib/requests/checksumrequest.py
@@ -1,13 +1,21 @@
+#!/usr/bin/env python3
 # -*- coding: utf-8 -*-
 
-from collections import OrderedDict
+"""Generic file checksum request."""
+
 import json
-from .. import credentials, devices
+from collections import OrderedDict
+
+from .. import credentials
 from .tclrequest import TclRequest
 from .tclresult import ChecksumResult
 
+
 class ChecksumRequest(TclRequest):
+    """Generic file checksum request."""
+
     def __init__(self, address, file_uri):
+        """Populate variables."""
         super().__init__()
         # NOTE: THIS HAS TO BE RUN ON AN ENCSLAVE
         self.uri = "/checksum.php"
@@ -16,9 +24,11 @@ class ChecksumRequest(TclRequest):
         self.file_uri = file_uri
 
     def get_headers(self):
+        """Return request headers."""
         return {"User-Agent": "tcl"}
 
     def get_params(self):
+        """Return request parameters."""
         params = OrderedDict()
         params.update(credentials.get_creds2())
         payload = {self.address: self.file_uri}
@@ -27,6 +37,7 @@ class ChecksumRequest(TclRequest):
         return params
 
     def is_done(self, http_status: int, contents: str) -> bool:
+        """Handle request result."""
         if http_status == 200:
             # <ENCRYPT_FOOTER>2abfa6f6507044fec995efede5d818e62a0b19b5</ENCRYPT_FOOTER> means ERROR (invalid ADDRESS!)
             if "<ENCRYPT_FOOTER>2abfa6f6507044fec995efede5d818e62a0b19b5</ENCRYPT_FOOTER>" in contents:
diff --git a/tcllib/requests/downloadrequest.py b/tcllib/requests/downloadrequest.py
index 345c247..ea05b52 100644
--- a/tcllib/requests/downloadrequest.py
+++ b/tcllib/requests/downloadrequest.py
@@ -1,5 +1,8 @@
+#!/usr/bin/env python3
 # -*- coding: utf-8 -*-
 
+"""Generic file download request."""
+
 import binascii
 import hashlib
 import random
@@ -7,6 +10,7 @@ import time
 import zlib
 from collections import OrderedDict
 from math import floor
+
 from .. import devices
 from .tclrequest import TclRequest
 from .tclresult import DownloadResult
@@ -21,6 +25,7 @@ def get_salt():
     tail = "{:06d}".format(random.randint(0, 999999))
     return "{}{}".format(str(millis), tail)
 
+
 def get_vk2(params_dict, cltp):
     """Generate salted hash of API parameters."""
     params_dict["cltp"] = cltp
@@ -36,8 +41,12 @@ def get_vk2(params_dict, cltp):
     hexhash = engine.hexdigest()
     return hexhash
 
+
 class DownloadRequest(TclRequest):
+    """Generic file download request."""
+
     def __init__(self, device: devices.Device, tvver: str, fw_id: str):
+        """Populate variables."""
         super().__init__()
         self.uri = "/download_request.php"
         self.method = "POST"
@@ -46,9 +55,11 @@ class DownloadRequest(TclRequest):
         self.fw_id = fw_id
 
     def get_headers(self):
-        return {"User-Agent": self.device.ua}
+        """Return request headers."""
+        return {"User-Agent": self.device.uagent}
 
     def get_params(self):
+        """Return request parameters."""
         params = OrderedDict()
         params["id"] = self.device.imei
         params["salt"] = get_salt()
@@ -68,6 +79,7 @@ class DownloadRequest(TclRequest):
         return params
 
     def is_done(self, http_status: int, contents: str) -> bool:
+        """Handle request result."""
         if http_status == 200:
             self.response = contents
             self.result = DownloadResult(contents)
diff --git a/tcllib/requests/encryptheaderrequest.py b/tcllib/requests/encryptheaderrequest.py
index e78f06a..fbaa352 100644
--- a/tcllib/requests/encryptheaderrequest.py
+++ b/tcllib/requests/encryptheaderrequest.py
@@ -1,12 +1,20 @@
+#!/usr/bin/env python3
 # -*- coding: utf-8 -*-
 
+"""Generic encrypted header download request."""
+
 from collections import OrderedDict
-from .. import credentials, devices
+
+from .. import credentials
 from .tclrequest import TclRequest
 from .tclresult import EncryptHeaderResult
 
+
 class EncryptHeaderRequest(TclRequest):
+    """Generic encrypted header download request."""
+
     def __init__(self, file_uri):
+        """Populate variables."""
         super().__init__()
         # NOTE: THIS HAS TO BE RUN ON AN ENCSLAVE
         self.uri = "/encrypt_header.php"
@@ -15,15 +23,18 @@ class EncryptHeaderRequest(TclRequest):
         self.file_uri = file_uri
 
     def get_headers(self):
+        """Return request headers."""
         return {"User-Agent": "tcl"}
 
     def get_params(self):
+        """Return request parameters."""
         params = OrderedDict()
         params.update(credentials.get_creds2())
         params["address"] = bytes(self.file_uri, "utf-8")
         return params
 
     def is_done(self, http_status: int, contents: str) -> bool:
+        """Handle request result."""
         # Expect "HTTP 206 Partial Content" response
         if http_status == 206:
             self.result = EncryptHeaderResult(contents)
diff --git a/tcllib/requests/http.py b/tcllib/requests/http.py
index 2b2821a..7aaf005 100644
--- a/tcllib/requests/http.py
+++ b/tcllib/requests/http.py
@@ -1,13 +1,21 @@
+#!/usr/bin/env python3
 # -*- coding: utf-8 -*-
 
-import requests
+"""Base HTTP requests."""
+
 from collections import OrderedDict
 
+import requests
+
+
 class TimeoutException(Exception):
+    """Ignore timeouts."""
     pass
 
+
 class HttpRequest:
     """Provides all generic features for making HTTP GET requests"""
+
     def __init__(self, url, timeout=10):
         self.url = url
         self.params = OrderedDict()
@@ -23,16 +31,18 @@ class HttpRequest:
         """Run query."""
         try:
             req = self.sess.get(self.url, params=self.params, timeout=self.timeout)
-        except requests.exceptions.Timeout as e:
-            raise TimeoutException(e)
+        except requests.exceptions.Timeout as exc:
+            raise TimeoutException(exc)
         return req
 
+
 class HttpPostRequest(HttpRequest):
     """Provides all generic features for making HTTP POST requests"""
+
     def run(self):
         """Run query."""
         try:
             req = self.sess.post(self.url, data=self.params, timeout=self.timeout)
-        except requests.exceptions.Timeout as e:
-            raise TimeoutException(e)
+        except requests.exceptions.Timeout as exc:
+            raise TimeoutException(exc)
         return req
diff --git a/tcllib/requests/runner.py b/tcllib/requests/runner.py
index 5569f89..cd7aca2 100644
--- a/tcllib/requests/runner.py
+++ b/tcllib/requests/runner.py
@@ -1,20 +1,28 @@
+#!/usr/bin/env python3
 # -*- coding: utf-8 -*-
 
+"""Generic request executors."""
+
+from . import http, serverselector
 from .tclrequest import TclRequest
-from . import http
-from . import serverselector
+
 
 class UnknownMethodException(Exception):
+    """Ignore unknown methods."""
     pass
 
+
 class RequestRunner:
+    """Generic request executor."""
+
     def __init__(self, server_selector: serverselector.ServerSelector, https=True):
+        """Populate variables."""
         self.server_selector = server_selector
         self.protocol = "https://" if https else "http://"
         self.max_tries = 5
 
     def get_http(self, method="GET") -> http.HttpRequest:
-        """Returns the http class according to desired method."""
+        """Return the http class according to desired method."""
         if method == "GET":
             return http.HttpRequest
         elif method == "POST":
@@ -22,11 +30,11 @@ class RequestRunner:
         raise UnknownMethodException("Unknown http method: {}".format(method))
 
     def get_server(self) -> str:
-        """Returns a master server."""
+        """Return a master server."""
         return self.server_selector.get_master_server()
 
     def run(self, query: TclRequest, timeout: int=10) -> bool:
-        """Runs the actual query."""
+        """Run the actual query."""
         for _ in range(0, self.max_tries):
             url = "{}{}{}".format(self.protocol, self.get_server(), query.uri)
             http_handler = self.get_http(query.method)(url, timeout)
diff --git a/tcllib/requests/serverselector.py b/tcllib/requests/serverselector.py
index cd2236f..1397512 100644
--- a/tcllib/requests/serverselector.py
+++ b/tcllib/requests/serverselector.py
@@ -1,12 +1,14 @@
+#!/usr/bin/env python3
 # -*- coding: utf-8 -*-
 
 # pylint: disable=C0111,C0326,C0103
 
 """Tools to sort API servers to find the least awful one."""
 
-import numpy
 import time
 
+import numpy
+
 
 MASTER_SERVERS = [
     "g2master-us-east.tclclouds.com",
@@ -17,6 +19,7 @@ MASTER_SERVERS = [
     "g2master-sa-east.tclclouds.com",
 ]
 
+
 class ServerSelector:
     """Returns a random server to use."""
 
@@ -45,6 +48,7 @@ class ServerSelector:
         """Hook to be called after request finished"""
         pass
 
+
 class ServerVoteSelector(ServerSelector):
     """Tries to return faster servers more often."""
 
diff --git a/tcllib/requests/tclrequest.py b/tcllib/requests/tclrequest.py
index 9d39607..c88492e 100644
--- a/tcllib/requests/tclrequest.py
+++ b/tcllib/requests/tclrequest.py
@@ -1,9 +1,16 @@
+#!/usr/bin/env python3
 # -*- coding: utf-8 -*-
 
+"""Generic TCL request object."""
+
 from . import tclresult
 
+
 class TclRequest:
+    """Generic TCL request object."""
+
     def __init__(self):
+        """Populate variables."""
         self.uri = ""
         self.rawmode = False
         self.response = None
@@ -12,15 +19,17 @@ class TclRequest:
         self.success = False
 
     def get_headers(self):
+        """Return request headers."""
         return {}
 
     def get_params(self):
+        """Return request parameters."""
         return {}
 
     def is_done(self, http_status: int, contents: str):
-        """Checks if query is done or needs retry."""
+        """Check if query is done or needs retry."""
         return False
 
     def get_result(self) -> tclresult.TclResult:
-        """Returns Result object."""
+        """Return Result object."""
         return self.result
diff --git a/tcllib/requests/tclresult.py b/tcllib/requests/tclresult.py
index 6b526b7..cb02852 100644
--- a/tcllib/requests/tclresult.py
+++ b/tcllib/requests/tclresult.py
@@ -1,5 +1,8 @@
+#!/usr/bin/env python3
 # -*- coding: utf-8 -*-
 
+"""Generic TCL API result handlers."""
+
 import xml.dom.minidom
 
 from defusedxml import ElementTree
@@ -8,12 +11,16 @@ from .. import dumpmgr
 
 
 class TclResult:
+    """Generic TCL API result."""
+
     def __init__(self, xmlstr: str):
+        """Populate variables."""
         self.raw_xml = xmlstr
         self.dumper = dumpmgr.DumpMgr()
         self.dumper.write_dump(xmlstr)
 
     def delete_dump(self):
+        """Delete last dump."""
         self.dumper.delete_last_dump()
 
     def pretty_xml(self):
@@ -21,8 +28,12 @@ class TclResult:
         mdx = xml.dom.minidom.parseString(self.raw_xml)
         return mdx.toprettyxml(indent="  ")
 
+
 class CheckResult(TclResult):
+    """Handle check request result."""
+
     def __init__(self, xmlstr: str):
+        """Extract data from check request result."""
         super().__init__(xmlstr)
         root = ElementTree.fromstring(xmlstr)
         self.curef = root.find("CUREF").text
@@ -35,8 +46,12 @@ class CheckResult(TclResult):
         self.filesize = fileinfo.find("SIZE").text
         self.filehash = fileinfo.find("CHECKSUM").text
 
+
 class DownloadResult(TclResult):
+    """Handle download request result."""
+
     def __init__(self, xmlstr: str):
+        """Extract data from download request result."""
         super().__init__(xmlstr)
         root = ElementTree.fromstring(xmlstr)
         file = root.find("FILE_LIST").find("FILE")
@@ -53,8 +68,12 @@ class DownloadResult(TclResult):
         self.encslaves = [s.text for s in enc_list]
         self.s3_slaves = [s.text for s in s3_slave_list]
 
+
 class ChecksumResult(TclResult):
+    """Handle checksum request result."""
+
     def __init__(self, xmlstr: str):
+        """Extract data from checksum request result."""
         super().__init__(xmlstr)
         root = ElementTree.fromstring(xmlstr)
         file = root.find("FILE_CHECKSUM_LIST").find("FILE")
@@ -63,6 +82,10 @@ class ChecksumResult(TclResult):
         self.sha1_footer = file.find("FOOTER").text
         self.sha1_body = file.find("BODY").text
 
+
 class EncryptHeaderResult(TclResult):
+    """Handle encrypted header request result."""
+
     def __init__(self, contents: str):
+        """Extract data from encrypted header request result."""
         self.rawdata = contents