Many minor code quality and readability improvements

6 files changed, 8 insertions, 9 deletions

diff --git a/dummyserver/handlers.py b/dummyserver/handlers.py
index 1d79f641..df5a0865 100644
--- a/dummyserver/handlers.py
+++ b/dummyserver/handlers.py
@@ -107,7 +107,7 @@ class TestingApp(RequestHandler):
     def certificate(self, request):
         """Return the requester's certificate."""
         cert = request.get_ssl_certificate()
-        subject = dict()
+        subject = {}
         if cert is not None:
             subject = {k: v for (k, v) in [y for z in cert["subject"] for y in z]}
         return Response(json.dumps(subject))
diff --git a/dummyserver/testcase.py b/dummyserver/testcase.py
index 60f0e9da..9c24d21b 100644
--- a/dummyserver/testcase.py
+++ b/dummyserver/testcase.py
@@ -182,7 +182,7 @@ class HTTPDummyProxyTestCase:
             app, cls.io_loop, None, "http", cls.proxy_host
         )
 
-        upstream_ca_certs = cls.https_certs.get("ca_certs", None)
+        upstream_ca_certs = cls.https_certs.get("ca_certs")
         app = web.Application(
             [(r".*", ProxyHandler)], upstream_ca_certs=upstream_ca_certs
         )
diff --git a/src/urllib3/contrib/securetransport.py b/src/urllib3/contrib/securetransport.py
index b7f86536..190d32f2 100644
--- a/src/urllib3/contrib/securetransport.py
+++ b/src/urllib3/contrib/securetransport.py
@@ -757,7 +757,7 @@ class SecureTransportContext:
 
     @verify_mode.setter
     def verify_mode(self, value):
-        self._verify = True if value == ssl.CERT_REQUIRED else False
+        self._verify = value == ssl.CERT_REQUIRED
 
     def set_default_verify_paths(self):
         # So, this has to do something a bit weird. Specifically, what it does
diff --git a/src/urllib3/response.py b/src/urllib3/response.py
index 2db95089..e00eaea2 100644
--- a/src/urllib3/response.py
+++ b/src/urllib3/response.py
@@ -272,7 +272,7 @@ class BaseHTTPResponse(io.IOBase):
                     for e in content_encoding.split(",")
                     if e.strip() in self.CONTENT_DECODERS
                 ]
-                if len(encodings):
+                if encodings:
                     self._decoder = _get_decoder(content_encoding)
 
     def _decode(self, data: bytes, decode_content: bool, flush_decoder: bool) -> bytes:
@@ -864,7 +864,7 @@ class HTTPResponse(BaseHTTPResponse):
         If the request that generated this response redirected, this method
         will return the final redirect location.
         """
-        if self.retries is not None and len(self.retries.history):
+        if self.retries is not None and self.retries.history:
             return self.retries.history[-1].redirect_location
         else:
             return self._request_url
diff --git a/src/urllib3/util/retry.py b/src/urllib3/util/retry.py
index 87b4a45a..53a78080 100644
--- a/src/urllib3/util/retry.py
+++ b/src/urllib3/util/retry.py
@@ -204,7 +204,7 @@ class Retry:
         self.backoff_factor = backoff_factor
         self.raise_on_redirect = raise_on_redirect
         self.raise_on_status = raise_on_status
-        self.history = history or tuple()
+        self.history = history or ()
         self.respect_retry_after_header = respect_retry_after_header
         self.remove_headers_on_redirect = frozenset(
             [h.lower() for h in remove_headers_on_redirect]
@@ -274,8 +274,7 @@ class Retry:
             retry_date = email.utils.mktime_tz(retry_date_tuple)
             seconds = retry_date - time.time()
 
-        if seconds < 0:
-            seconds = 0
+        seconds = max(seconds, 0)
 
         return seconds
 
diff --git a/src/urllib3/util/url.py b/src/urllib3/util/url.py
index 91ee9761..34912a1b 100644
--- a/src/urllib3/util/url.py
+++ b/src/urllib3/util/url.py
@@ -241,7 +241,7 @@ def _remove_path_dot_segments(path: str) -> str:
         if segment == ".":
             continue
         # Anything other than '..', should be appended to the output
-        elif segment != "..":
+        if segment != "..":
             output.append(segment)
         # In this case segment == '..', if we can, we should pop the last
         # element