Empty sequences are false, there's no need to check the len.

gunicorn/arbiter.py

@@ -205,7 +205,7 @@ class Arbiter(object):
             while True:
                 self.maybe_promote_master()
 
-                sig = self.SIG_QUEUE.pop(0) if len(self.SIG_QUEUE) else None
+                sig = self.SIG_QUEUE.pop(0, None)
                 if sig is None:
                     self.sleep()
                     self.murder_workers()

gunicorn/http/body.py

@@ -210,7 +210,7 @@ class Body(object):
 
         while size > self.buf.tell():
             data = self.reader.read(1024)
-            if not len(data):
+            if not data:
                 break
             self.buf.write(data)
 
@@ -248,7 +248,7 @@ class Body(object):
     def readlines(self, size=None):
         ret = []
         data = self.read()
-        while len(data):
+        while data:
             pos = data.find(b"\n")
             if pos < 0:
                 ret.append(data)

gunicorn/http/message.py

@@ -64,7 +64,7 @@ class Message(object):
 
         # Parse headers into key/value pairs paying attention
         # to continuation lines.
-        while len(lines):
+        while lines:
             if len(headers) >= self.limit_request_fields:
                 raise LimitRequestHeaders("limit request headers fields")
 
@@ -81,7 +81,7 @@ class Message(object):
             name, value = name.strip(), [value.lstrip()]
 
             # Consume value continuation lines
-            while len(lines) and lines[0].startswith((" ", "\t")):
+            while lines and lines[0].startswith((" ", "\t")):
                 curr = lines.pop(0)
                 header_length += len(curr)
                 if header_length > self.limit_request_field_size > 0:

gunicorn/http/unreader.py

@@ -40,7 +40,7 @@ class Unreader(object):
 
         while self.buf.tell() < size:
             chunk = self.chunk()
-            if not len(chunk):
+            if not chunk:
                 ret = self.buf.getvalue()
                 self.buf = six.BytesIO()
                 return ret

gunicorn/instrument/statsd.py

@@ -80,7 +80,7 @@ class Statsd(Logger):
                         pass
 
             # Log to parent logger only if there is something to say
-            if msg is not None and len(msg) > 0:
+            if msg:
                 Logger.log(self, lvl, msg, *args, **kwargs)
         except Exception:
             Logger.warning(self, "Failed to log to statsd", exc_info=True)

tests/treq.py

@@ -74,7 +74,7 @@ class request(object):
             yield lines[:pos+2]
             lines = lines[pos+2:]
             pos = lines.find(b"\r\n")
-        if len(lines):
+        if lines:
             yield lines
 
     def send_bytes(self):
@@ -137,7 +137,7 @@ class request(object):
     def match_read(self, req, body, sizes):
         data = self.szread(req.body.read, sizes)
         count = 1000
-        while len(body):
+        while body:
             if body[:len(data)] != data:
                 raise AssertionError("Invalid body data read: %r != %r" % (
                                         data, body[:len(data)]))
@@ -148,9 +148,9 @@ class request(object):
             if count <= 0:
                 raise AssertionError("Unexpected apparent EOF")
 
-        if len(body):
+        if body:
             raise AssertionError("Failed to read entire body: %r" % body)
-        elif len(data):
+        elif data:
             raise AssertionError("Read beyond expected body: %r" % data)
         data = req.body.read(sizes())
         if data:
@@ -159,7 +159,7 @@ class request(object):
     def match_readline(self, req, body, sizes):
         data = self.szread(req.body.readline, sizes)
         count = 1000
-        while len(body):
+        while body:
             if body[:len(data)] != data:
                 raise AssertionError("Invalid data read: %r" % data)
             if b'\n' in data[:-1]:
@@ -170,9 +170,9 @@ class request(object):
                 count -= 1
             if count <= 0:
                 raise AssertionError("Apparent unexpected EOF")
-        if len(body):
+        if body:
             raise AssertionError("Failed to read entire body: %r" % body)
-        elif len(data):
+        elif data:
             raise AssertionError("Read beyond expected body: %r" % data)
         data = req.body.readline(sizes())
         if data:
@@ -190,7 +190,7 @@ class request(object):
                 raise AssertionError("Invalid body data read: %r != %r" % (
                                                     line, body[:len(line)]))
             body = body[len(line):]
-        if len(body):
+        if body:
             raise AssertionError("Failed to read entire body: %r" % body)
         data = req.body.readlines(sizes())
         if data:
@@ -207,7 +207,7 @@ class request(object):
                 raise AssertionError("Invalid body data read: %r != %r" % (
                                                     line, body[:len(line)]))
             body = body[len(line):]
-        if len(body):
+        if body:
             raise AssertionError("Failed to read entire body: %r" % body)
         try:
             data = six.next(iter(req.body))
@@ -254,7 +254,7 @@ class request(object):
         p = RequestParser(cfg, sender())
         for req in p:
             self.same(req, sizer, matcher, cases.pop(0))
-        assert len(cases) == 0
+        assert not cases
 
     def same(self, req, sizer, matcher, exp):
         assert req.method == exp["method"]