diff --git a/brozzler/__init__.py b/brozzler/__init__.py
index 4062fbd..2150190 100644
--- a/brozzler/__init__.py
+++ b/brozzler/__init__.py
@@ -17,10 +17,13 @@ See the License for the specific language governing permissions and
 limitations under the License.
 """
 
+import datetime
 import logging
+import threading
 from importlib.metadata import version as _version
 
 import structlog
+import urlcanon
 
 __version__ = _version("brozzler")
 
@@ -91,7 +94,7 @@ def _logging_handler_handle(self, record):
         finally:
             try:
                 self.release()
-            except:
+            except:  # noqa: E722
                 pass
     return rv
 
@@ -108,7 +111,6 @@ def behaviors(behaviors_dir=None):
     `js-templates/`. Defaults to brozzler dir.
     """
     import os
-    import string
 
     import yaml
 
@@ -125,7 +127,6 @@ def behavior_script(url, template_parameters=None, behaviors_dir=None):
     """
     Returns the javascript behavior string populated with template_parameters.
     """
-    import json
     import re
 
     logger = structlog.get_logger(logger_name=__name__)
@@ -194,8 +195,6 @@ class ThreadExceptionGate:
         return "<ThreadExceptionGate(%s)>" % self.thread
 
 
-import threading
-
 _thread_exception_gates = {}
 _thread_exception_gates_lock = threading.Lock()
 
@@ -225,7 +224,7 @@ def thread_exception_gate(thread=None):
         thread = threading.current_thread()
 
     with _thread_exception_gates_lock:
-        if not thread in _thread_exception_gates:
+        if thread not in _thread_exception_gates:
             _thread_exception_gates[thread] = ThreadExceptionGate(thread)
 
     return _thread_exception_gates[thread]
@@ -252,7 +251,6 @@ def thread_raise(thread, exctype):
     """
     import ctypes
     import inspect
-    import threading
 
     import structlog
 
@@ -322,9 +320,6 @@ def jinja2_environment(behaviors_dir=None):
     return _jinja2_env
 
 
-import urlcanon
-
-
 def _remove_query(url):
     url.question_mark = b""
     url.query = b""
@@ -403,13 +398,10 @@ def suggest_default_chrome_exe():
     return "chromium-browser"
 
 
-import datetime
-
 EPOCH_UTC = datetime.datetime.fromtimestamp(0.0, tz=datetime.timezone.utc)
 
-
-from brozzler.browser import Browser, BrowserPool, BrowsingException
-from brozzler.robots import is_permitted_by_robots
+from brozzler.browser import Browser, BrowserPool, BrowsingException  # noqa: E402
+from brozzler.robots import is_permitted_by_robots  # noqa: E402
 
 __all__ = [
     "is_permitted_by_robots",
@@ -422,22 +414,25 @@ __all__ = [
     "suggest_default_chrome_exe",
 ]
 
+# TODO try using importlib.util.find_spec to test for dependency presence
+# rather than try/except on import.
+# See https://docs.astral.sh/ruff/rules/unused-import/#example
 try:
-    import doublethink
+    import doublethink  # noqa: F401
 
     # All of these imports use doublethink for real and are unsafe
     # to do if doublethink is unavailable.
-    from brozzler.frontier import RethinkDbFrontier
+    from brozzler.frontier import RethinkDbFrontier  # noqa: F401
     from brozzler.model import (
-        InvalidJobConf,
-        Job,
-        Page,
-        Site,
-        new_job,
-        new_job_file,
-        new_site,
+        InvalidJobConf,  # noqa: F401
+        Job,  # noqa: F401
+        Page,  # noqa: F401
+        Site,  # noqa: F401
+        new_job,  # noqa: F401
+        new_job_file,  # noqa: F401
+        new_site,  # noqa: F401
     )
-    from brozzler.worker import BrozzlerWorker
+    from brozzler.worker import BrozzlerWorker  # noqa: F401
 
     __all__.extend(
         [
diff --git a/brozzler/browser.py b/brozzler/browser.py
index 6b872e4..4e42438 100644
--- a/brozzler/browser.py
+++ b/brozzler/browser.py
@@ -18,7 +18,6 @@ limitations under the License.
 
 import base64
 import datetime
-import itertools
 import json
 import logging
 import socket
@@ -213,7 +212,7 @@ class WebsockReceiverThread(threading.Thread):
     def _on_message(self, websock, message):
         try:
             self._handle_message(websock, message)
-        except:
+        except:  # noqa: E722
             self.logger.exception(
                 "uncaught exception in _handle_message",
                 message=message,
@@ -430,7 +429,7 @@ class Browser:
                 self.logger.info("shutting down websocket connection")
                 try:
                     self.websock.close()
-                except BaseException as e:
+                except BaseException:
                     self.logger.exception(
                         "exception closing websocket", websocket=self.websock
                     )
@@ -458,7 +457,7 @@ class Browser:
                         )
 
             self.websock_url = None
-        except:
+        except:  # noqa: E722
             self.logger.exception("problem stopping")
 
     def is_running(self):
@@ -628,7 +627,7 @@ class Browser:
                 jpeg_bytes = self.screenshot(full_page)
                 on_screenshot(jpeg_bytes)
                 return
-            except BrowsingTimeout as e:
+            except BrowsingTimeout:
                 self.logger.exception("attempt %s/3", i + 1)
 
     def visit_hashtags(self, page_url, hashtags, outlinks):
@@ -807,12 +806,12 @@ class Browser:
                 if (
                     msg
                     and "result" in msg
-                    and not ("exceptionDetails" in msg["result"])
+                    and "exceptionDetails" not in msg["result"]
                     and not (
                         "wasThrown" in msg["result"] and msg["result"]["wasThrown"]
                     )
                     and "result" in msg["result"]
-                    and type(msg["result"]["result"]["value"]) == bool
+                    and isinstance(msg["result"]["result"]["value"], bool)
                     and msg["result"]["result"]["value"]
                 ):
                     self.logger.info("behavior decided it has finished")
diff --git a/brozzler/chrome.py b/brozzler/chrome.py
index 7dd6066..3332d71 100644
--- a/brozzler/chrome.py
+++ b/brozzler/chrome.py
@@ -265,7 +265,7 @@ class Chrome:
                     return url
             except brozzler.ShutdownRequested:
                 raise
-            except Exception as e:
+            except Exception:
                 if time.time() - self._last_warning > 30:
                     url_logger.warning(
                         "problem accessing url (will keep trying until timeout)",
@@ -325,7 +325,7 @@ class Chrome:
                     self.logger.debug(
                         "chrome pid %s STDERR %s", self.chrome_process.pid, buf
                     )
-        except:
+        except:  # noqa: E722
             self.logger.exception("unexpected exception")
 
     def stop(self):
@@ -378,7 +378,7 @@ class Chrome:
             self.chrome_process.stderr.close()
             try:
                 self._home_tmpdir.cleanup()
-            except:
+            except:  # noqa: E722
                 self.logger.exception(
                     "exception deleting self._home_tmpdir", tmpdir=self._home_tmpdir
                 )
diff --git a/brozzler/cli.py b/brozzler/cli.py
index 1fe5318..f18ad14 100755
--- a/brozzler/cli.py
+++ b/brozzler/cli.py
@@ -23,12 +23,10 @@ import datetime
 import json
 import logging
 import os
-import re
 import signal
 import string
 import sys
 import threading
-import time
 import traceback
 import warnings
 
@@ -397,9 +395,9 @@ def brozzle_page(argv=None):
             enable_youtube_dl=not worker._skip_youtube_dl,
         )
         logger.info("outlinks", outlinks=sorted(outlinks))
-    except brozzler.ReachedLimit as e:
+    except brozzler.ReachedLimit:
         logger.exception("reached limit")
-    except brozzler.PageInterstitialShown as e:
+    except brozzler.PageInterstitialShown:
         logger.exception("page interstitial shown")
     finally:
         browser.stop()
@@ -661,7 +659,7 @@ def brozzler_worker(argv=None):
             logger.info(
                 "dumping state (caught signal)\n%s", signal=signum, state=state_strs
             )
-        except BaseException as e:
+        except BaseException:
             logger.exception("exception dumping state")
         finally:
             signal.signal(signal.SIGQUIT, dump_state)
@@ -672,11 +670,11 @@ def brozzler_worker(argv=None):
         try:
             # make set from seed IDs in SKIP_AV_SEEDS_FILE
             with open(SKIP_AV_SEEDS_FILE) as skips:
-                skip_av_seeds = {int(l) for l in skips.readlines()}
+                skip_av_seeds = {int(line) for line in skips.readlines()}
                 logger.info(
                     "running with skip_av_seeds file", skip_av_seeds=SKIP_AV_SEEDS_FILE
                 )
-        except Exception as e:
+        except Exception:
             skip_av_seeds = set()
             logger.info("running with empty skip_av_seeds")
         return skip_av_seeds
@@ -686,13 +684,13 @@ def brozzler_worker(argv=None):
         try:
             # make list from file
             with open(YTDLP_PROXY_ENDPOINTS_FILE) as endpoints:
-                ytdlp_proxy_endpoints = [l for l in endpoints.readlines()]
+                ytdlp_proxy_endpoints = [line for line in endpoints.readlines()]
                 if ytdlp_proxy_endpoints:
                     logger.info(
                         "running with ytdlp proxy endpoints file",
                         ytdlp_proxy_endpoints=YTDLP_PROXY_ENDPOINTS_FILE,
                     )
-        except Exception as e:
+        except Exception:
             ytdlp_proxy_endpoints = []
             logger.info("running with empty proxy endpoints file")
         return ytdlp_proxy_endpoints
@@ -1032,7 +1030,7 @@ def brozzler_purge(argv=None):
     configure_logging(args)
 
     rr = rethinker(args)
-    frontier = brozzler.RethinkDbFrontier(rr)
+    brozzler.RethinkDbFrontier(rr)
     if args.job:
         try:
             job_id = int(args.job)
diff --git a/brozzler/dashboard/__init__.py b/brozzler/dashboard/__init__.py
index 15a836c..13ea214 100644
--- a/brozzler/dashboard/__init__.py
+++ b/brozzler/dashboard/__init__.py
@@ -17,9 +17,14 @@ See the License for the specific language governing permissions and
 limitations under the License.
 """
 
+import base64
+import os
 import sys
 
+import doublethink
+import rethinkdb as rdb
 import structlog
+import yaml
 
 logger = structlog.get_logger(logger_name=__name__)
 
@@ -33,14 +38,6 @@ except ImportError as e:
         e,
     )
     sys.exit(1)
-import base64
-import importlib
-import json
-import os
-
-import doublethink
-import rethinkdb as rdb
-import yaml
 
 r = rdb.RethinkDB()
 
@@ -285,6 +282,8 @@ def root(path):
 
 
 try:
+    import logging
+
     import gunicorn.app.base
     import gunicorn.glogging
     from gunicorn.six import iteritems
diff --git a/brozzler/easy.py b/brozzler/easy.py
index fc213f8..d8e8762 100644
--- a/brozzler/easy.py
+++ b/brozzler/easy.py
@@ -18,10 +18,22 @@ See the License for the specific language governing permissions and
 limitations under the License.
 """
 
+import argparse
+import os
+import signal
+import socket
+import socketserver
 import sys
+import threading
+import time
+import traceback
 
+import doublethink
 import structlog
 
+import brozzler
+import brozzler.cli
+
 logger = structlog.get_logger(logger_name=__name__)
 
 try:
@@ -42,19 +54,6 @@ except ImportError as e:
         exc_info=True,
     )
     sys.exit(1)
-import argparse
-import os
-import signal
-import socket
-import socketserver
-import threading
-import time
-import traceback
-
-import doublethink
-
-import brozzler
-import brozzler.cli
 
 
 def _build_arg_parser(argv=None):
diff --git a/brozzler/frontier.py b/brozzler/frontier.py
index b37d5d1..6e1ac63 100644
--- a/brozzler/frontier.py
+++ b/brozzler/frontier.py
@@ -16,10 +16,6 @@ See the License for the specific language governing permissions and
 limitations under the License.
 """
 
-import datetime
-import random
-import time
-
 import doublethink
 import rethinkdb as rdb
 import structlog
@@ -47,11 +43,11 @@ class RethinkDbFrontier:
         db_logger = self.logger.bind(dbname=self.rr.dbname)
 
         dbs = self.rr.db_list().run()
-        if not self.rr.dbname in dbs:
+        if self.rr.dbname not in dbs:
             db_logger.info("creating rethinkdb database")
             self.rr.db_create(self.rr.dbname).run()
         tables = self.rr.table_list().run()
-        if not "sites" in tables:
+        if "sites" not in tables:
             db_logger.info("creating rethinkdb table 'sites' in database")
             self.rr.table_create(
                 "sites", shards=self.shards, replicas=self.replicas
@@ -60,7 +56,7 @@ class RethinkDbFrontier:
                 "sites_last_disclaimed", [r.row["status"], r.row["last_disclaimed"]]
             ).run()
             self.rr.table("sites").index_create("job_id").run()
-        if not "pages" in tables:
+        if "pages" not in tables:
             db_logger.info("creating rethinkdb table 'pages' in database")
             self.rr.table_create(
                 "pages", shards=self.shards, replicas=self.replicas
@@ -80,7 +76,7 @@ class RethinkDbFrontier:
                 "least_hops",
                 [r.row["site_id"], r.row["brozzle_count"], r.row["hops_from_seed"]],
             ).run()
-        if not "jobs" in tables:
+        if "jobs" not in tables:
             db_logger.info("creating rethinkdb table 'jobs' in database")
             self.rr.table_create(
                 "jobs", shards=self.shards, replicas=self.replicas
@@ -352,7 +348,6 @@ class RethinkDbFrontier:
         site.save()
 
     def _build_fresh_page(self, site, parent_page, url, hops_off=0):
-        url_for_scoping = urlcanon.semantic(url)
         url_for_crawling = urlcanon.whatwg(url)
         hashtag = (url_for_crawling.hash_sign + url_for_crawling.fragment).decode(
             "utf-8"
@@ -461,8 +456,8 @@ class RethinkDbFrontier:
         # "rethinkdb.errors.ReqlDriverError: Query size (167883036) greater than maximum (134217727) in:"
         # there can be many pages and each one can be very large (many videos,
         # in and out of scope links, etc)
-        l = list(pages.values())
-        for batch in (l[i : i + 50] for i in range(0, len(l), 50)):
+        pages_list = list(pages.values())
+        for batch in (pages_list[i : i + 50] for i in range(0, len(pages_list), 50)):
             try:
                 self.logger.debug("inserting/replacing batch of %s pages", len(batch))
                 reql = self.rr.table("pages").insert(batch, conflict="replace")
@@ -471,8 +466,8 @@ class RethinkDbFrontier:
                     'conflict="replace")',
                     batch,
                 )
-                result = reql.run()
-            except Exception as e:
+                reql.run()
+            except Exception:
                 self.logger.exception(
                     "problem inserting/replacing batch of %s pages",
                     len(batch),
diff --git a/brozzler/model.py b/brozzler/model.py
index 49a9905..38b371a 100644
--- a/brozzler/model.py
+++ b/brozzler/model.py
@@ -19,12 +19,9 @@ limitations under the License.
 
 import base64
 import copy
-import datetime
 import hashlib
 import json
 import os
-import re
-import time
 import urllib
 import uuid
 import zlib
@@ -61,7 +58,7 @@ class InvalidJobConf(Exception):
             # debugged, I found it here. Maybe there's a better way to see it.
             value = validator._errors[0].info[0][0].info[0][0].value
             self.errors["bad value"] = value
-        except:
+        except:  # noqa: E722
             value = None
 
 
@@ -122,10 +119,10 @@ def new_job(frontier, job_conf):
     # rethinkdb.errors.ReqlDriverError: Query size (167883036) greater than maximum (134217727) in:
     for batch in (pages[i : i + 500] for i in range(0, len(pages), 500)):
         logger.info("inserting batch of %s pages", len(batch))
-        result = frontier.rr.table("pages").insert(batch).run()
+        frontier.rr.table("pages").insert(batch).run()
     for batch in (sites[i : i + 100] for i in range(0, len(sites), 100)):
         logger.info("inserting batch of %s sites", len(batch))
-        result = frontier.rr.table("sites").insert(batch).run()
+        frontier.rr.table("sites").insert(batch).run()
     logger.info("job fully started", job_id=job.id)
 
     return job
@@ -200,9 +197,9 @@ class Job(doublethink.Document, ElapsedMixIn):
     table = "jobs"
 
     def populate_defaults(self):
-        if not "status" in self:
+        if "status" not in self:
             self.status = "ACTIVE"
-        if not "starts_and_stops" in self:
+        if "starts_and_stops" not in self:
             if self.get("started"):  # backward compatibility
                 self.starts_and_stops = [
                     {"start": self.get("started"), "stop": self.get("finished")}
@@ -229,28 +226,28 @@ class Site(doublethink.Document, ElapsedMixIn):
     table = "sites"
 
     def populate_defaults(self):
-        if not "status" in self:
+        if "status" not in self:
             self.status = "ACTIVE"
-        if not "claimed" in self:
+        if "claimed" not in self:
             self.claimed = False
-        if not "last_disclaimed" in self:
+        if "last_disclaimed" not in self:
             self.last_disclaimed = brozzler.EPOCH_UTC
-        if not "last_claimed" in self:
+        if "last_claimed" not in self:
             self.last_claimed = brozzler.EPOCH_UTC
-        if not "scope" in self:
+        if "scope" not in self:
             self.scope = {}
-        if not "skip_ytdlp" in self:
+        if "skip_ytdlp" not in self:
             self.skip_ytdlp = None
 
         # backward compatibility
         if "surt" in self.scope:
-            if not "accepts" in self.scope:
+            if "accepts" not in self.scope:
                 self.scope["accepts"] = []
             self.scope["accepts"].append({"surt": self.scope["surt"]})
             del self.scope["surt"]
 
         # backward compatibility
-        if "max_hops_off_surt" in self.scope and not "max_hops_off" in self.scope:
+        if "max_hops_off_surt" in self.scope and "max_hops_off" not in self.scope:
             self.scope["max_hops_off"] = self.scope["max_hops_off_surt"]
         if "max_hops_off_surt" in self.scope:
             del self.scope["max_hops_off_surt"]
@@ -260,7 +257,7 @@ class Site(doublethink.Document, ElapsedMixIn):
                 brozzler.site_surt_canon(self.seed).ssurt().decode("ascii")
             )
 
-        if not "starts_and_stops" in self:
+        if "starts_and_stops" not in self:
             if self.get("start_time"):  # backward compatibility
                 self.starts_and_stops = [
                     {"start": self.get("start_time"), "stop": None}
@@ -275,7 +272,7 @@ class Site(doublethink.Document, ElapsedMixIn):
         return 'Site({"id":"%s","seed":"%s",...})' % (self.id, self.seed)
 
     def _accept_ssurt_if_not_redundant(self, ssurt):
-        if not "accepts" in self.scope:
+        if "accepts" not in self.scope:
             self.scope["accepts"] = []
         simple_rule_ssurts = (
             rule["ssurt"]
@@ -334,7 +331,7 @@ class Site(doublethink.Document, ElapsedMixIn):
         if not isinstance(url, urlcanon.ParsedUrl):
             url = urlcanon.semantic(url)
 
-        if not url.scheme in (b"http", b"https"):
+        if url.scheme not in (b"http", b"https"):
             # XXX doesn't belong here maybe (where? worker ignores unknown
             # schemes?)
             return False
@@ -390,31 +387,31 @@ class Page(doublethink.Document):
         return hashlib.sha1(digest_this.encode("utf-8")).hexdigest()
 
     def populate_defaults(self):
-        if not "retry_after" in self:
+        if "retry_after" not in self:
             self.retry_after = None
-        if not "failed_attempts" in self:
+        if "failed_attempts" not in self:
             self.failed_attempts = 0
-        if not "hops_from_seed" in self:
+        if "hops_from_seed" not in self:
             self.hops_from_seed = 0
-        if not "hop_path" in self:
+        if "hop_path" not in self:
             self.hop_path = None
-        if not "via_page_url" in self:
+        if "via_page_url" not in self:
             self.via_page_url = None
-        if not "brozzle_count" in self:
+        if "brozzle_count" not in self:
             self.brozzle_count = 0
-        if not "claimed" in self:
+        if "claimed" not in self:
             self.claimed = False
-        if "hops_off_surt" in self and not "hops_off" in self:
+        if "hops_off_surt" in self and "hops_off" not in self:
             self.hops_off = self.hops_off_surt
         if "hops_off_surt" in self:
             del self["hops_off_surt"]
-        if not "hops_off" in self:
+        if "hops_off" not in self:
             self.hops_off = 0
-        if not "needs_robots_check" in self:
+        if "needs_robots_check" not in self:
             self.needs_robots_check = False
-        if not "priority" in self:
+        if "priority" not in self:
             self.priority = self._calc_priority()
-        if not "id" in self:
+        if "id" not in self:
             self.id = self.compute_id(self.site_id, self.url)
 
     def __str__(self):
diff --git a/brozzler/pywb.py b/brozzler/pywb.py
index b4b6280..2f70614 100644
--- a/brozzler/pywb.py
+++ b/brozzler/pywb.py
@@ -18,9 +18,16 @@ See the License for the specific language governing permissions and
 limitations under the License.
 """
 
+import argparse
+import json
 import sys
 
+import doublethink
+import rethinkdb as rdb
 import structlog
+import urlcanon
+
+import brozzler
 
 logger = structlog.get_logger(logger_name=__name__)
 
@@ -40,14 +47,7 @@ except ImportError as e:
         e,
     )
     sys.exit(1)
-import argparse
-import json
 
-import doublethink
-import rethinkdb as rdb
-import urlcanon
-
-import brozzler
 
 r = rdb.RethinkDB()
 
@@ -137,7 +137,7 @@ class TheGoodUrlCanonicalizer(object):
             key = urlcanon.semantic(url).surt().decode("ascii")
             # logging.debug('%s -> %s', url, key)
             return key
-        except Exception as e:
+        except Exception:
             return url
 
     def replace_default_canonicalizer():
@@ -221,18 +221,9 @@ def support_in_progress_warcs():
 
 class SomeWbUrl(pywb.rewrite.wburl.WbUrl):
     def __init__(self, orig_url):
-        import re
-
         import six
         from pywb.rewrite.wburl import WbUrl
-        from pywb.utils.loaders import to_native_str
-        from six.moves.urllib.parse import (
-            quote,
-            quote_plus,
-            unquote_plus,
-            urlsplit,
-            urlunsplit,
-        )
+        from six.moves.urllib.parse import quote
 
         pywb.rewrite.wburl.BaseWbUrl.__init__(self)
 
@@ -320,7 +311,6 @@ def _fuzzy_query_call(self, query):
     urlkey = to_native_str(query.key, "utf-8")
     url = query.url
     filter_ = query.filters
-    output = query.output
 
     for rule in self.rules.iter_matching(urlkey):
         m = rule.regex.search(urlkey)
diff --git a/brozzler/robots.py b/brozzler/robots.py
index 7f249dd..2e0bd67 100644
--- a/brozzler/robots.py
+++ b/brozzler/robots.py
@@ -71,7 +71,7 @@ _robots_caches = {}  # {site_id:reppy.cache.RobotsCache}
 
 
 def _robots_cache(site, proxy=None):
-    if not site.id in _robots_caches:
+    if site.id not in _robots_caches:
         req_sesh = _SessionRaiseOn420()
         req_sesh.verify = False  # ignore cert errors
         if proxy:
diff --git a/brozzler/worker.py b/brozzler/worker.py
index 3a58bfa..807195b 100644
--- a/brozzler/worker.py
+++ b/brozzler/worker.py
@@ -21,9 +21,7 @@ limitations under the License.
 import datetime
 import io
 import json
-import random
 import socket
-import tempfile
 import threading
 import time
 import urllib.request
@@ -99,9 +97,13 @@ class BrozzlerWorker:
         self._skip_visit_hashtags = skip_visit_hashtags
         self._skip_youtube_dl = skip_youtube_dl
 
+        # TODO try using importlib.util.find_spec to test for dependency
+        # presence rather than try/except on import.
+        # See https://docs.astral.sh/ruff/rules/unused-import/#example
+
         # We definitely shouldn't ytdlp if the optional extra is missing
         try:
-            import yt_dlp
+            import yt_dlp  # noqa: F401
         except ImportError:
             self.logger.info(
                 "optional yt-dlp extra not installed; setting skip_youtube_dl to True"
@@ -200,7 +202,7 @@ class BrozzlerWorker:
                     response = requests.get("http://%s/status" % self._proxy)
                     status = json.loads(response.text)
                     self._proxy_is_warcprox = status["role"] == "warcprox"
-                except Exception as e:
+                except Exception:
                     self._proxy_is_warcprox = False
                 self.logger.info(
                     "%s %s warcprox",
@@ -348,13 +350,13 @@ class BrozzlerWorker:
                     )
                     metrics.brozzler_ydl_urls_checked.inc(1)
                     outlinks.update(ydl_outlinks)
-                except brozzler.ReachedLimit as e:
+                except brozzler.ReachedLimit:
                     raise
                 except brozzler.ShutdownRequested:
                     raise
                 except brozzler.ProxyError:
                     raise
-                except brozzler.VideoExtractorError as e:
+                except brozzler.VideoExtractorError:
                     self.logger.exception("error extracting video info")
                 except Exception as e:
                     if (
@@ -391,9 +393,9 @@ class BrozzlerWorker:
                 timeout=self.HEADER_REQUEST_TIMEOUT,
             ) as r:
                 return r.headers
-        except requests.exceptions.Timeout as e:
+        except requests.exceptions.Timeout:
             url_logger.warning("Timed out trying to get headers", exc_info=True)
-        except requests.exceptions.RequestException as e:
+        except requests.exceptions.RequestException:
             url_logger.warning("Failed to get headers", exc_info=True)
         return {}
 
@@ -469,7 +471,7 @@ class BrozzlerWorker:
                 if "content-range" in response_headers:
                     video["content-range"] = response_headers["content-range"]
                 self.logger.debug("embedded video", video=video)
-                if not "videos" in page:
+                if "videos" not in page:
                     page.videos = []
                 page.videos.append(video)
 
@@ -598,13 +600,13 @@ class BrozzlerWorker:
             site_logger.info("no pages left for site")
         except brozzler.ReachedLimit as e:
             self._frontier.reached_limit(site, e)
-        except brozzler.ReachedTimeLimit as e:
+        except brozzler.ReachedTimeLimit:
             self._frontier.finished(site, "FINISHED_TIME_LIMIT")
         except brozzler.CrawlStopped:
             self._frontier.finished(site, "FINISHED_STOP_REQUESTED")
         # except brozzler.browser.BrowsingAborted:
         #     self.logger.info("{} shut down".format(browser))
-        except brozzler.ProxyError as e:
+        except brozzler.ProxyError:
             if self._warcprox_auto:
                 self.logger.exception(
                     "proxy error, will try to choose a "
@@ -676,7 +678,7 @@ class BrozzlerWorker:
         try:
             self.status_info = self._service_registry.heartbeat(status_info)
             self.logger.debug("status in service registry", status=self.status_info)
-        except r.ReqlError as e:
+        except r.ReqlError:
             self.logger.exception(
                 "failed to send heartbeat and update service registry",
                 info=status_info,
@@ -748,11 +750,11 @@ class BrozzlerWorker:
                 time.sleep(0.5)
 
             self.logger.warn("shutdown requested")
-        except r.ReqlError as e:
+        except r.ReqlError:
             self.logger.exception("caught rethinkdb exception, will try to proceed")
         except brozzler.ShutdownRequested:
             self.logger.info("shutdown requested")
-        except:
+        except:  # noqa: E722
             self.logger.critical(
                 "thread exiting due to unexpected exception", exc_info=True
             )
@@ -760,7 +762,7 @@ class BrozzlerWorker:
             if self._service_registry and hasattr(self, "status_info"):
                 try:
                     self._service_registry.unregister(self.status_info["id"])
-                except:
+                except:  # noqa: E722
                     self.logger.exception("failed to unregister from service registry")
 
             self.logger.info(
diff --git a/brozzler/ydl.py b/brozzler/ydl.py
index f81d551..df2fe82 100644
--- a/brozzler/ydl.py
+++ b/brozzler/ydl.py
@@ -101,7 +101,7 @@ def _build_youtube_dl(worker, destdir, site, page, ytdlp_proxy_endpoints):
             if result_type in ("url", "url_transparent"):
                 if "extraction_depth" in extra_info:
                     self.logger.info(
-                        f"Following redirect",
+                        "Following redirect",
                         redirect_url=ie_result["url"],
                         extraction_depth=extra_info["extraction_depth"],
                     )
@@ -136,7 +136,7 @@ def _build_youtube_dl(worker, destdir, site, page, ytdlp_proxy_endpoints):
                     # use it later to extract the watch pages as outlinks.
                     try:
                         ie_result["entries_no_dl"] = list(ie_result["entries"])
-                    except Exception as e:
+                    except Exception:
                         extract_context.warning(
                             "failed to unroll entries ie_result['entries']?",
                             exc_info=True,
@@ -166,7 +166,7 @@ def _build_youtube_dl(worker, destdir, site, page, ytdlp_proxy_endpoints):
                     import magic
 
                     mimetype = magic.from_file(info_dict["filepath"], mime=True)
-                except ImportError as e:
+                except ImportError:
                     mimetype = "video/%s" % info_dict["ext"]
                     self.logger.warning(
                         "guessing mimetype due to error",
@@ -236,7 +236,7 @@ def _build_youtube_dl(worker, destdir, site, page, ytdlp_proxy_endpoints):
                 )
                 site.last_claimed = doublethink.utcnow()
                 site.save()
-        except:
+        except:  # noqa: E722
             worker.logger.debug(
                 "problem heartbeating site.last_claimed site",
                 id=site.id,
@@ -316,7 +316,7 @@ def _remember_videos(page, pushed_videos=None):
     """
     Saves info about videos captured by yt-dlp in `page.videos`.
     """
-    if not "videos" in page:
+    if "videos" not in page:
         page.videos = []
     for pushed_video in pushed_videos or []:
         video = {
@@ -351,7 +351,7 @@ def _try_youtube_dl(worker, ydl, site, page):
                 )
             metrics.brozzler_ydl_extract_successes.labels(ydl.is_youtube_host).inc(1)
             break
-        except brozzler.ShutdownRequested as e:
+        except brozzler.ShutdownRequested:
             raise
         except Exception as e:
             if (
diff --git a/tests/test_brozzling.py b/tests/test_brozzling.py
index 03124a4..3a62919 100755
--- a/tests/test_brozzling.py
+++ b/tests/test_brozzling.py
@@ -110,7 +110,7 @@ def test_httpd(httpd):
     of the same url return the same payload, proving it can be used to test
     deduplication.
     """
-    payload1 = content2 = None
+    payload1 = None
     url = "http://localhost:%s/site1/file1.txt" % httpd.server_port
     with urllib.request.urlopen(url) as response:
         assert response.status == 200
@@ -175,7 +175,6 @@ def test_420(httpd):
 
 def test_js_dialogs(httpd):
     chrome_exe = brozzler.suggest_default_chrome_exe()
-    url = "http://localhost:%s/site4/alert.html" % httpd.server_port
     with brozzler.Browser(chrome_exe=chrome_exe) as browser:
         # before commit d2ed6b97a24 these would hang and eventually raise
         # brozzler.browser.BrowsingTimeout, which would cause this test to fail
diff --git a/tests/test_cli.py b/tests/test_cli.py
index 3c8f0c5..3f9c382 100644
--- a/tests/test_cli.py
+++ b/tests/test_cli.py
@@ -40,11 +40,11 @@ def cli_commands():
     commands = set(console_scripts().keys())
     commands.remove("brozzler-wayback")
     try:
-        import gunicorn
+        import gunicorn  # noqa: F401
     except ImportError:
         commands.remove("brozzler-dashboard")
     try:
-        import pywb
+        import pywb  # noqa: F401
     except ImportError:
         commands.remove("brozzler-easy")
     return commands
diff --git a/tests/test_cluster.py b/tests/test_cluster.py
index 5949fd3..58e9d13 100644
--- a/tests/test_cluster.py
+++ b/tests/test_cluster.py
@@ -23,7 +23,6 @@ import http.server
 import os
 import socket
 import subprocess
-import sys
 import threading
 import time
 import urllib.request
@@ -47,7 +46,7 @@ def _local_address():
     try:
         s.connect(("10.255.255.255", 1))  # ip doesn't need to be reachable
         return s.getsockname()[0]
-    except:
+    except:  # noqa: E722
         return "127.0.0.1"
     finally:
         s.close()
@@ -148,7 +147,7 @@ def test_httpd(httpd):
     of the same url return the same payload, proving it can be used to test
     deduplication.
     """
-    payload1 = content2 = None
+    payload1 = None
     url = make_url(httpd, "/site1/file1.txt")
     with urllib.request.urlopen(url) as response:
         assert response.status == 200
@@ -351,8 +350,8 @@ def test_warcprox_auto(httpd):
 
 
 def test_proxy_conflict():
-    with pytest.raises(AssertionError) as excinfo:
-        worker = brozzler.worker.BrozzlerWorker(
+    with pytest.raises(AssertionError):
+        brozzler.worker.BrozzlerWorker(
             None, None, warcprox_auto=True, proxy="localhost:12345"
         )
 
@@ -523,7 +522,6 @@ def test_login(httpd):
 
     # take a look at the captures table
     time.sleep(2)  # in case warcprox hasn't finished processing urls
-    robots_url = make_url(httpd, "/robots.txt")
     captures = list(
         rr.table("captures").filter({"test_id": test_id}).order_by("timestamp").run()
     )
@@ -730,7 +728,6 @@ def test_redirect_hashtags(httpd):
 
 
 def test_stop_crawl(httpd):
-    test_id = "test_stop_crawl_job-%s" % datetime.datetime.utcnow().isoformat()
     rr = doublethink.Rethinker("localhost", db="brozzler")
     frontier = brozzler.RethinkDbFrontier(rr)
 
@@ -804,7 +801,6 @@ def test_warcprox_outage_resiliency(httpd):
     """
     rr = doublethink.Rethinker("localhost", db="brozzler")
     frontier = brozzler.RethinkDbFrontier(rr)
-    svcreg = doublethink.ServiceRegistry(rr)
 
     # run two instances of warcprox
     opts = warcprox.Options()
@@ -836,7 +832,7 @@ def test_warcprox_outage_resiliency(httpd):
         # the system, if any
         try:
             stop_service("warcprox")
-        except Exception as e:
+        except Exception:
             logger.warning("problem stopping warcprox service: %s", exc_info=True)
 
         # queue the site for brozzling
@@ -917,7 +913,6 @@ def test_warcprox_outage_resiliency(httpd):
 
 
 def test_time_limit(httpd):
-    test_id = "test_time_limit-%s" % datetime.datetime.utcnow().isoformat()
     rr = doublethink.Rethinker("localhost", db="brozzler")
     frontier = brozzler.RethinkDbFrontier(rr)
 
@@ -928,7 +923,6 @@ def test_time_limit(httpd):
 
     sites = list(frontier.job_sites(job.id))
     assert len(sites) == 1
-    site = sites[0]
 
     # time limit should be enforced pretty soon
     start = time.time()
@@ -986,7 +980,7 @@ def test_ydl_stitching(httpd):
     time.sleep(2)  # in case warcprox hasn't finished processing urls
     # take a look at the captures table
     captures = list(rr.table("captures").filter({"test_id": test_id}).run())
-    l = [c for c in captures if c["url"] == stitched_url]
+    l = [c for c in captures if c["url"] == stitched_url]  # noqa: E741
     assert len(l) == 1
     c = l[0]
     assert c["filename"].startswith("test_ydl_stitching")
diff --git a/tests/test_frontier.py b/tests/test_frontier.py
index 31628c4..a29e8e2 100644
--- a/tests/test_frontier.py
+++ b/tests/test_frontier.py
@@ -559,7 +559,7 @@ def test_parent_url_scoping():
     assert parent_page.outlinks["accepted"] == outlinks
 
     # parent page redirect_url matches accept parent_url_regex
-    parent_page_c = brozzler.Page(
+    brozzler.Page(
         rr,
         {
             "site_id": site.id,
@@ -606,7 +606,7 @@ def test_parent_url_scoping():
     assert parent_page.outlinks["accepted"] == []
 
     # parent page redirect_url matches block parent_url_regex
-    parent_page_c = brozzler.Page(
+    brozzler.Page(
         rr,
         {
             "site_id": site.id,
@@ -659,10 +659,10 @@ def test_completed_page():
         ]
     }
     assert page.brozzle_count == 1
-    assert page.claimed == False
+    assert page.claimed is False
     page.refresh()
     assert page.brozzle_count == 1
-    assert page.claimed == False
+    assert page.claimed is False
 
     # redirect that doesn't change scope surt because destination is covered by
     # the original surt
@@ -686,10 +686,10 @@ def test_completed_page():
     site.refresh()
     assert site.scope == {"accepts": [{"ssurt": "com,example,//http:/a/"}]}
     assert page.brozzle_count == 1
-    assert page.claimed == False
+    assert page.claimed is False
     page.refresh()
     assert page.brozzle_count == 1
-    assert page.claimed == False
+    assert page.claimed is False
 
     # redirect that doesn't change scope surt because page is not the seed page
     site = brozzler.Site(rr, {"seed": "http://example.com/a/"})
@@ -712,10 +712,10 @@ def test_completed_page():
     site.refresh()
     assert site.scope == {"accepts": [{"ssurt": "com,example,//http:/a/"}]}
     assert page.brozzle_count == 1
-    assert page.claimed == False
+    assert page.claimed is False
     page.refresh()
     assert page.brozzle_count == 1
-    assert page.claimed == False
+    assert page.claimed is False
 
 
 def test_seed_page():
@@ -931,7 +931,7 @@ def test_max_claimed_sites():
     claimed_sites = frontier.claim_sites(3)
     assert len(claimed_sites) == 2
     with pytest.raises(brozzler.NothingToClaim):
-        claimed_site = frontier.claim_sites(3)
+        frontier.claim_sites(3)
 
     # clean slate for the next one
     rr.table("jobs").delete().run()
@@ -1074,7 +1074,7 @@ def test_max_hops_off():
     site.refresh()  # get it back from the db
 
     # renamed this param
-    assert not "max_hops_off_surt" in site.scope
+    assert "max_hops_off_surt" not in site.scope
     assert site.scope["max_hops_off"] == 1
 
     seed_page = frontier.seed_page(site.id)
@@ -1109,7 +1109,7 @@ def test_max_hops_off():
     assert len(pages) == 4
     assert pages[0].url == "http://example.com/"
     assert pages[0].hops_off == 0
-    assert not "hops_off_surt" in pages[0]
+    assert "hops_off_surt" not in pages[0]
     assert set(pages[0].outlinks["accepted"]) == {
         "https://example.com/toot",
         "http://foo.org/",
diff --git a/tests/test_units.py b/tests/test_units.py
index 33979bc..55399de 100644
--- a/tests/test_units.py
+++ b/tests/test_units.py
@@ -21,7 +21,6 @@ import datetime
 import http.server
 import os
 import socket
-import sys
 import tempfile
 import threading
 import time
@@ -29,7 +28,6 @@ import uuid
 from unittest import mock
 
 import pytest
-import requests
 import yaml
 
 import brozzler
@@ -291,7 +289,7 @@ def test_proxy_down():
             )
 
         # youtube-dl fetch
-        with tempfile.TemporaryDirectory(prefix="brzl-ydl-") as tempdir:
+        with tempfile.TemporaryDirectory(prefix="brzl-ydl-"):
             with pytest.raises(brozzler.ProxyError):
                 brozzler.ydl.do_youtube_dl(worker, site, page)
 
@@ -315,7 +313,7 @@ def test_start_stop_backwards_compat():
     assert len(site.starts_and_stops) == 1
     assert site.starts_and_stops[0]["start"]
     assert site.starts_and_stops[0]["stop"] is None
-    assert not "start_time" in site
+    assert "start_time" not in site
 
     site = brozzler.Site(
         None,
@@ -324,13 +322,13 @@ def test_start_stop_backwards_compat():
     assert len(site.starts_and_stops) == 1
     assert site.starts_and_stops[0]["start"] == datetime.datetime(2017, 1, 1)
     assert site.starts_and_stops[0]["stop"] is None
-    assert not "start_time" in site
+    assert "start_time" not in site
 
     job = brozzler.Job(None, {"seeds": [{"url": "https://example.com/"}]})
     assert job.starts_and_stops[0]["start"]
     assert job.starts_and_stops[0]["stop"] is None
-    assert not "started" in job
-    assert not "finished" in job
+    assert "started" not in job
+    assert "finished" not in job
 
     job = brozzler.Job(
         None,
@@ -342,8 +340,8 @@ def test_start_stop_backwards_compat():
     )
     assert job.starts_and_stops[0]["start"] == datetime.datetime(2017, 1, 1)
     assert job.starts_and_stops[0]["stop"] == datetime.datetime(2017, 1, 2)
-    assert not "started" in job
-    assert not "finished" in job
+    assert "started" not in job
+    assert "finished" not in job
 
 
 class Exception1(Exception):
@@ -452,9 +450,9 @@ def test_thread_raise_second_with_block():
             with brozzler.thread_accept_exceptions():
                 time.sleep(2)
             return  # test fails
-        except Exception1 as e:
+        except Exception1:
             pass
-        except:
+        except:  # noqa: E722
             return  # fail test
 
         try:
diff --git a/vagrant/vagrant-brozzler-new-site.py b/vagrant/vagrant-brozzler-new-site.py
index b76ff84..a2632b7 100755
--- a/vagrant/vagrant-brozzler-new-site.py
+++ b/vagrant/vagrant-brozzler-new-site.py
@@ -32,7 +32,7 @@ import sys
 
 try:
     from shlex import quote
-except:
+except:  # noqa: E722
     from pipes import quote