From 5e4efd7d73c74b39a79fb7ac2dd70f88ccbc866a Mon Sep 17 00:00:00 2001
From: Denis Afonso <denis.afonso@gmail.com>
Date: Wed, 16 Nov 2016 22:49:45 +0000
Subject: [PATCH] Some minor improvements on coding style.

Fixes issue #464
---
 examples/cacheclt.py                     | 11 ++++----
 examples/cachesvr.py                     |  4 ++-
 examples/child_process.py                |  6 +++-
 examples/crawl.py                        | 15 +++++-----
 examples/echo_client_tulip.py            |  3 ++
 examples/echo_server_tulip.py            |  3 ++
 examples/fetch0.py                       |  8 +++---
 examples/fetch1.py                       | 21 ++++++++------
 examples/fetch2.py                       | 35 ++++++++++++++----------
 examples/fetch3.py                       | 28 +++++++++----------
 examples/fuzz_as_completed.py            | 26 ++++++++++--------
 examples/qspeed.py                       |  9 +++++-
 examples/shell.py                        |  8 +++++-
 examples/simple_tcp_server.py            |  9 +++---
 examples/sink.py                         | 11 ++++----
 examples/source.py                       | 18 ++++++------
 examples/source1.py                      | 15 +++++-----
 examples/stacks.py                       | 24 ++++++++--------
 examples/subprocess_attach_read_pipe.py  |  7 ++++-
 examples/subprocess_attach_write_pipe.py | 10 +++++--
 examples/subprocess_shell.py             |  8 ++++--
 examples/tcp_echo.py                     |  6 +++-
 examples/timing_tcp_server.py            |  6 ++--
 examples/udp_echo.py                     |  4 +++
 24 files changed, 180 insertions(+), 115 deletions(-)

diff --git a/examples/cacheclt.py b/examples/cacheclt.py
index b11a4d1a..c7c75bc5 100644
--- a/examples/cacheclt.py
+++ b/examples/cacheclt.py
@@ -4,11 +4,12 @@
 """
 
 import argparse
-import asyncio
-from asyncio import test_utils
 import json
 import logging
 
+import asyncio
+
+
 ARGS = argparse.ArgumentParser(description='Cache client example.')
 ARGS.add_argument(
     '--tls', action='store_true', dest='tls',
@@ -106,7 +107,7 @@ def activity(self):
                 self.reader, self.writer = yield from asyncio.open_connection(
                     self.host, self.port, ssl=self.sslctx, loop=self.loop)
             except Exception as exc:
-                backoff = min(args.max_backoff, backoff + (backoff//2) + 1)
+                backoff = min(args.max_backoff, backoff + (backoff // 2) + 1)
                 logging.info('Error connecting: %r; sleep %s', exc, backoff)
                 yield from asyncio.sleep(backoff, loop=self.loop)
                 continue
@@ -172,7 +173,7 @@ def main():
         loop = asyncio.new_event_loop()
     sslctx = None
     if args.tls:
-        sslctx = test_utils.dummy_ssl_context()
+        sslctx = asyncio.test_utils.dummy_ssl_context()
     cache = CacheClient(args.host, args.port, sslctx=sslctx, loop=loop)
     try:
         loop.run_until_complete(
@@ -191,7 +192,7 @@ def w(g):
 
     key = 'foo-%s' % label
     while True:
-        logging.info('%s %s', label, '-'*20)
+        logging.info('%s %s', label, '-' * 20)
         try:
             ret = yield from w(cache.set(key, 'hello-%s-world' % label))
             logging.info('%s set %s', label, ret)
diff --git a/examples/cachesvr.py b/examples/cachesvr.py
index 053f9c21..2f50a77a 100644
--- a/examples/cachesvr.py
+++ b/examples/cachesvr.py
@@ -57,12 +57,14 @@
 """
 
 import argparse
-import asyncio
 import json
 import logging
 import os
 import random
 
+import asyncio
+
+
 ARGS = argparse.ArgumentParser(description='Cache server example.')
 ARGS.add_argument(
     '--tls', action='store_true', dest='tls',
diff --git a/examples/child_process.py b/examples/child_process.py
index 3fac175e..a03fce81 100644
--- a/examples/child_process.py
+++ b/examples/child_process.py
@@ -26,6 +26,7 @@
 # Return a write-only transport wrapping a writable pipe
 #
 
+
 @asyncio.coroutine
 def connect_write_pipe(file):
     loop = asyncio.get_event_loop()
@@ -36,10 +37,12 @@ def connect_write_pipe(file):
 # Wrap a readable pipe in a stream
 #
 
+
 @asyncio.coroutine
 def connect_read_pipe(file):
     loop = asyncio.get_event_loop()
     stream_reader = asyncio.StreamReader(loop=loop)
+
     def factory():
         return asyncio.StreamReaderProtocol(stream_reader)
     transport, _ = yield from loop.connect_read_pipe(factory, file)
@@ -85,7 +88,7 @@ def writeall(fd, buf):
     stderr, stderr_transport = yield from connect_read_pipe(p.stderr)
 
     # interact with subprocess
-    name = {stdout:'OUT', stderr:'ERR'}
+    name = {stdout: 'OUT', stderr: 'ERR'}
     registered = {asyncio.Task(stderr.readline()): stderr,
                   asyncio.Task(stdout.readline()): stdout}
     while registered:
@@ -116,6 +119,7 @@ def writeall(fd, buf):
     stdout_transport.close()
     stderr_transport.close()
 
+
 if __name__ == '__main__':
     if sys.platform == 'win32':
         loop = ProactorEventLoop()
diff --git a/examples/crawl.py b/examples/crawl.py
index 4cb76d26..c081a231 100644
--- a/examples/crawl.py
+++ b/examples/crawl.py
@@ -15,15 +15,16 @@
 # - Handle out of file descriptors directly?  (How?)
 
 import argparse
-import asyncio
-import asyncio.locks
-import cgi
-from http.client import BadStatusLine
 import logging
 import re
 import sys
 import time
 import urllib.parse
+import cgi
+from http.client import BadStatusLine
+
+import asyncio
+import asyncio.locks
 
 
 ARGS = argparse.ArgumentParser(description="Web crawler")
@@ -341,7 +342,7 @@ def send_request(self):
         self.headers.append(('User-Agent', 'asyncio-example-crawl/0.0'))
         self.headers.append(('Host', self.netloc))
         self.headers.append(('Accept', '*/*'))
-        ##self.headers.append(('Accept-Encoding', 'gzip'))
+        # self.headers.append(('Accept-Encoding', 'gzip'))
         for key, value in self.headers:
             line = '%s: %s' % (key, value)
             yield from self.putline(line)
@@ -519,7 +520,7 @@ def fetch(self):
                 self.exceptions.append(exc)
                 self.log(1, 'try', self.tries, 'for', self.url,
                             'raised', repr(exc))
-                ##import pdb; pdb.set_trace()
+                # import pdb; pdb.set_trace()
                 # Don't reuse the connection in this case.
             finally:
                 if self.request is not None:
@@ -534,7 +535,7 @@ def fetch(self):
             self.next_url = urllib.parse.urljoin(self.url, next_url)
             if self.max_redirect > 0:
                 self.log(1, 'redirect to', self.next_url, 'from', self.url)
-                self.crawler.add_url(self.next_url, self.max_redirect-1)
+                self.crawler.add_url(self.next_url, self.max_redirect - 1)
             else:
                 self.log(0, 'redirect limit reached for', self.next_url,
                             'from', self.url)
diff --git a/examples/echo_client_tulip.py b/examples/echo_client_tulip.py
index 88124efe..0bd10335 100644
--- a/examples/echo_client_tulip.py
+++ b/examples/echo_client_tulip.py
@@ -1,7 +1,9 @@
 import asyncio
 
+
 END = b'Bye-bye!\n'
 
+
 @asyncio.coroutine
 def echo_client():
     reader, writer = yield from asyncio.open_connection('localhost', 8000)
@@ -15,6 +17,7 @@ def echo_client():
             break
     writer.close()
 
+
 loop = asyncio.get_event_loop()
 loop.run_until_complete(echo_client())
 loop.close()
diff --git a/examples/echo_server_tulip.py b/examples/echo_server_tulip.py
index 8167e540..8b98e9a8 100644
--- a/examples/echo_server_tulip.py
+++ b/examples/echo_server_tulip.py
@@ -1,9 +1,11 @@
 import asyncio
 
+
 @asyncio.coroutine
 def echo_server():
     yield from asyncio.start_server(handle_connection, 'localhost', 8000)
 
+
 @asyncio.coroutine
 def handle_connection(reader, writer):
     while True:
@@ -12,6 +14,7 @@ def handle_connection(reader, writer):
             break
         writer.write(data)
 
+
 loop = asyncio.get_event_loop()
 loop.run_until_complete(echo_server())
 try:
diff --git a/examples/fetch0.py b/examples/fetch0.py
index 2712abdd..c31a3571 100644
--- a/examples/fetch0.py
+++ b/examples/fetch0.py
@@ -2,12 +2,12 @@
 
 import sys
 
-from asyncio import get_event_loop, open_connection, coroutine
+import asyncio
 
 
-@coroutine
+@asyncio.coroutine
 def fetch():
-    r, w = yield from open_connection('python.org', 80)
+    r, w = yield from asyncio.open_connection('python.org', 80)
     request = 'GET / HTTP/1.0\r\n\r\n'
     print('>', request, file=sys.stderr)
     w.write(request.encode('latin-1'))
@@ -23,7 +23,7 @@ def fetch():
 
 
 def main():
-    loop = get_event_loop()
+    loop = asyncio.get_event_loop()
     try:
         body = loop.run_until_complete(fetch())
     finally:
diff --git a/examples/fetch1.py b/examples/fetch1.py
index 7f5d8873..190c9565 100644
--- a/examples/fetch1.py
+++ b/examples/fetch1.py
@@ -6,7 +6,7 @@
 import sys
 import urllib.parse
 
-from asyncio import get_event_loop, open_connection, coroutine
+import asyncio
 
 
 class Response:
@@ -18,27 +18,30 @@ def __init__(self, verbose=True):
         self.reason = None  # 'Ok'
         self.headers = []  # [('Content-Type', 'text/html')]
 
-    @coroutine
+    @asyncio.coroutine
     def read(self, reader):
-        @coroutine
+        @asyncio.coroutine
         def getline():
             return (yield from reader.readline()).decode('latin-1').rstrip()
         status_line = yield from getline()
-        if self.verbose: print('<', status_line, file=sys.stderr)
+        if self.verbose:
+            print('<', status_line, file=sys.stderr)
         self.http_version, status, self.reason = status_line.split(None, 2)
         self.status = int(status)
         while True:
             header_line = yield from getline()
             if not header_line:
                 break
-            if self.verbose: print('<', header_line, file=sys.stderr)
+            if self.verbose:
+                print('<', header_line, file=sys.stderr)
             # TODO: Continuation lines.
             key, value = header_line.split(':', 1)
             self.headers.append((key, value.strip()))
-        if self.verbose: print(file=sys.stderr)
+        if self.verbose:
+            print(file=sys.stderr)
 
 
-@coroutine
+@asyncio.coroutine
 def fetch(url, verbose=True):
     parts = urllib.parse.urlparse(url)
     if parts.scheme == 'http':
@@ -57,7 +60,7 @@ def fetch(url, verbose=True):
     request = 'GET %s HTTP/1.0\r\n\r\n' % path
     if verbose:
         print('>', request, file=sys.stderr, end='')
-    r, w = yield from open_connection(parts.hostname, port, ssl=ssl)
+    r, w = yield from asyncio.open_connection(parts.hostname, port, ssl=ssl)
     w.write(request.encode('latin-1'))
     response = Response(verbose)
     yield from response.read(r)
@@ -66,7 +69,7 @@ def fetch(url, verbose=True):
 
 
 def main():
-    loop = get_event_loop()
+    loop = asyncio.get_event_loop()
     try:
         body = loop.run_until_complete(fetch(sys.argv[1], '-v' in sys.argv))
     finally:
diff --git a/examples/fetch2.py b/examples/fetch2.py
index a75f7ba7..3ca9d1f1 100644
--- a/examples/fetch2.py
+++ b/examples/fetch2.py
@@ -7,7 +7,7 @@
 import urllib.parse
 from http.client import BadStatusLine
 
-from asyncio import get_event_loop, open_connection, coroutine
+import asyncio
 
 
 class Request:
@@ -34,13 +34,13 @@ def __init__(self, url, verbose=True):
         self.reader = None
         self.writer = None
 
-    @coroutine
+    @asyncio.coroutine
     def connect(self):
         if self.verbose:
             print('* Connecting to %s:%s using %s' %
                   (self.hostname, self.port, 'ssl' if self.ssl else 'tcp'),
                   file=sys.stderr)
-        self.reader, self.writer = yield from open_connection(self.hostname,
+        self.reader, self.writer = yield from asyncio.open_connection(self.hostname,
                                                               self.port,
                                                               ssl=self.ssl)
         if self.verbose:
@@ -51,20 +51,22 @@ def connect(self):
     def putline(self, line):
         self.writer.write(line.encode('latin-1') + b'\r\n')
 
-    @coroutine
+    @asyncio.coroutine
     def send_request(self):
         request = '%s %s %s' % (self.method, self.full_path, self.http_version)
-        if self.verbose: print('>', request, file=sys.stderr)
+        if self.verbose:
+            print('>', request, file=sys.stderr)
         self.putline(request)
         if 'host' not in {key.lower() for key, _ in self.headers}:
             self.headers.insert(0, ('Host', self.netloc))
         for key, value in self.headers:
             line = '%s: %s' % (key, value)
-            if self.verbose: print('>', line, file=sys.stderr)
+            if self.verbose:
+                print('>', line, file=sys.stderr)
             self.putline(line)
         self.putline('')
 
-    @coroutine
+    @asyncio.coroutine
     def get_response(self):
         response = Response(self.reader, self.verbose)
         yield from response.read_headers()
@@ -81,14 +83,15 @@ def __init__(self, reader, verbose=True):
         self.reason = None  # 'Ok'
         self.headers = []  # [('Content-Type', 'text/html')]
 
-    @coroutine
+    @asyncio.coroutine
     def getline(self):
         return (yield from self.reader.readline()).decode('latin-1').rstrip()
 
-    @coroutine
+    @asyncio.coroutine
     def read_headers(self):
         status_line = yield from self.getline()
-        if self.verbose: print('<', status_line, file=sys.stderr)
+        if self.verbose:
+            print('<', status_line, file=sys.stderr)
         status_parts = status_line.split(None, 2)
         if len(status_parts) != 3:
             raise BadStatusLine(status_line)
@@ -98,13 +101,15 @@ def read_headers(self):
             header_line = yield from self.getline()
             if not header_line:
                 break
-            if self.verbose: print('<', header_line, file=sys.stderr)
+            if self.verbose:
+                print('<', header_line, file=sys.stderr)
             # TODO: Continuation lines.
             key, value = header_line.split(':', 1)
             self.headers.append((key, value.strip()))
-        if self.verbose: print(file=sys.stderr)
+        if self.verbose:
+            print(file=sys.stderr)
 
-    @coroutine
+    @asyncio.coroutine
     def read(self):
         nbytes = None
         for key, value in self.headers:
@@ -118,7 +123,7 @@ def read(self):
         return body
 
 
-@coroutine
+@asyncio.coroutine
 def fetch(url, verbose=True):
     request = Request(url, verbose)
     yield from request.connect()
@@ -129,7 +134,7 @@ def fetch(url, verbose=True):
 
 
 def main():
-    loop = get_event_loop()
+    loop = asyncio.get_event_loop()
     try:
         body = loop.run_until_complete(fetch(sys.argv[1], '-v' in sys.argv))
     finally:
diff --git a/examples/fetch3.py b/examples/fetch3.py
index 00cc33a5..9771eb2d 100644
--- a/examples/fetch3.py
+++ b/examples/fetch3.py
@@ -8,7 +8,7 @@
 import urllib.parse
 from http.client import BadStatusLine
 
-from asyncio import get_event_loop, open_connection, coroutine
+import asyncio
 
 
 class ConnectionPool:
@@ -22,10 +22,10 @@ def close(self):
         for _, writer in self.connections.values():
             writer.close()
 
-    @coroutine
+    @asyncio.coroutine
     def open_connection(self, host, port, ssl):
         port = port or (443 if ssl else 80)
-        ipaddrs = yield from get_event_loop().getaddrinfo(host, port)
+        ipaddrs = yield from asyncio.get_event_loop().getaddrinfo(host, port)
         if self.verbose:
             print('* %s resolves to %s' %
                   (host, ', '.join(ip[4][0] for ip in ipaddrs)),
@@ -41,7 +41,7 @@ def open_connection(self, host, port, ssl):
                 if self.verbose:
                     print('* Reusing pooled connection', key, file=sys.stderr)
                 return conn
-        reader, writer = yield from open_connection(host, port, ssl=ssl)
+        reader, writer = yield from asyncio.open_connection(host, port, ssl=ssl)
         host, port, *_ = writer.get_extra_info('peername')
         key = host, port, ssl
         self.connections[key] = reader, writer
@@ -78,7 +78,7 @@ def vprint(self, *args):
         if self.verbose:
             print(*args, file=sys.stderr)
 
-    @coroutine
+    @asyncio.coroutine
     def connect(self, pool):
         self.vprint('* Connecting to %s:%s using %s' %
                     (self.hostname, self.port, 'ssl' if self.ssl else 'tcp'))
@@ -89,13 +89,13 @@ def connect(self, pool):
         self.vprint('* Connected to %s' %
                     (self.writer.get_extra_info('peername'),))
 
-    @coroutine
+    @asyncio.coroutine
     def putline(self, line):
         self.vprint('>', line)
         self.writer.write(line.encode('latin-1') + b'\r\n')
-        ##yield from self.writer.drain()
+        # yield from self.writer.drain()
 
-    @coroutine
+    @asyncio.coroutine
     def send_request(self):
         request = '%s %s %s' % (self.method, self.full_path, self.http_version)
         yield from self.putline(request)
@@ -106,7 +106,7 @@ def send_request(self):
             yield from self.putline(line)
         yield from self.putline('')
 
-    @coroutine
+    @asyncio.coroutine
     def get_response(self):
         response = Response(self.reader, self.verbose)
         yield from response.read_headers()
@@ -127,13 +127,13 @@ def vprint(self, *args):
         if self.verbose:
             print(*args, file=sys.stderr)
 
-    @coroutine
+    @asyncio.coroutine
     def getline(self):
         line = (yield from self.reader.readline()).decode('latin-1').rstrip()
         self.vprint('<', line)
         return line
 
-    @coroutine
+    @asyncio.coroutine
     def read_headers(self):
         status_line = yield from self.getline()
         status_parts = status_line.split(None, 2)
@@ -161,7 +161,7 @@ def get_header(self, key, default=None):
                 return v
         return default
 
-    @coroutine
+    @asyncio.coroutine
     def read(self):
         nbytes = None
         for key, value in self.headers:
@@ -192,7 +192,7 @@ def read(self):
         return body
 
 
-@coroutine
+@asyncio.coroutine
 def fetch(url, verbose=True, max_redirect=10):
     pool = ConnectionPool(verbose)
     try:
@@ -218,7 +218,7 @@ def main():
         loop = ProactorEventLoop()
         set_event_loop(loop)
     else:
-        loop = get_event_loop()
+        loop = asyncio.get_event_loop()
     try:
         body = loop.run_until_complete(fetch(sys.argv[1], '-v' in sys.argv))
     finally:
diff --git a/examples/fuzz_as_completed.py b/examples/fuzz_as_completed.py
index 123fbf1b..90cffaaa 100644
--- a/examples/fuzz_as_completed.py
+++ b/examples/fuzz_as_completed.py
@@ -2,18 +2,21 @@
 
 """Fuzz tester for as_completed(), by Glenn Langford."""
 
-import asyncio
 import itertools
 import random
 import sys
 
+import asyncio
+
+
 @asyncio.coroutine
 def sleeper(time):
     yield from asyncio.sleep(time)
     return time
 
+
 @asyncio.coroutine
-def watcher(tasks,delay=False):
+def watcher(tasks, delay=False):
     res = []
     for t in asyncio.as_completed(tasks):
         r = yield from t
@@ -22,8 +25,8 @@ def watcher(tasks,delay=False):
             # simulate processing delay
             process_time = random.random() / 10
             yield from asyncio.sleep(process_time)
-    #print(res)
-    #assert(sorted(res) == res)
+    # print(res)
+    # assert(sorted(res) == res)
     if sorted(res) != res:
         print('FAIL', res)
         print('------------')
@@ -31,25 +34,26 @@ def watcher(tasks,delay=False):
         print('.', end='')
         sys.stdout.flush()
 
+
 loop = asyncio.get_event_loop()
 
 print('Pass 1')
 # All permutations of discrete task running times must be returned
 # by as_completed in the correct order.
-task_times = [0, 0.1, 0.2, 0.3, 0.4 ] # 120 permutations
+task_times = [0, 0.1, 0.2, 0.3, 0.4]  # 120 permutations
 for times in itertools.permutations(task_times):
-    tasks = [ asyncio.Task(sleeper(t)) for t in times ]
+    tasks = [asyncio.Task(sleeper(t)) for t in times]
     loop.run_until_complete(asyncio.Task(watcher(tasks)))
 
 print()
 print('Pass 2')
 # Longer task times, with randomized duplicates. 100 tasks each time.
-longer_task_times = [x/10 for x in range(30)]
+longer_task_times = [x / 10 for x in range(30)]
 for i in range(20):
     task_times = longer_task_times * 10
     random.shuffle(task_times)
-    #print('Times', task_times[:500])
-    tasks = [ asyncio.Task(sleeper(t)) for t in task_times[:100] ]
+    # print('Times', task_times[:500])
+    tasks = [asyncio.Task(sleeper(t)) for t in task_times[:100]]
     loop.run_until_complete(asyncio.Task(watcher(tasks)))
 
 print()
@@ -61,8 +65,8 @@ def watcher(tasks,delay=False):
 for i in range(20):
     task_times = longer_task_times * 10
     random.shuffle(task_times)
-    #print('Times', task_times[:200])
-    tasks = [ asyncio.Task(sleeper(t)) for t in task_times[:200] ]
+    # print('Times', task_times[:200])
+    tasks = [asyncio.Task(sleeper(t)) for t in task_times[:200]]
     loop.run_until_complete(asyncio.Task(watcher(tasks, delay=True)))
 
 print()
diff --git a/examples/qspeed.py b/examples/qspeed.py
index fcd71168..7e92276f 100644
--- a/examples/qspeed.py
+++ b/examples/qspeed.py
@@ -2,7 +2,10 @@
 """How fast is the queue implementation?"""
 
 import time
+
 import asyncio
+
+
 print(asyncio)
 
 N_CONSUMERS = 10
@@ -10,6 +13,7 @@
 N_ITEMS = 100000  # Per producer
 Q_SIZE = 1
 
+
 @asyncio.coroutine
 def producer(q):
     for i in range(N_ITEMS):
@@ -17,6 +21,7 @@ def producer(q):
     for i in range(N_CONSUMERS):
         yield from q.put(None)
 
+
 @asyncio.coroutine
 def consumer(q):
     while True:
@@ -24,6 +29,7 @@ def consumer(q):
         if i is None:
             break
 
+
 def main():
     q = asyncio.Queue(Q_SIZE)
     loop = asyncio.get_event_loop()
@@ -38,6 +44,7 @@ def main():
           N_ITEMS, 'items/producer;',
           Q_SIZE, 'maxsize;',
           '%.3f total seconds;' % dt,
-          '%.3f usec per item.' % (1e6*dt/N_ITEMS/N_PRODUCERS))
+          '%.3f usec per item.' % (1e6 * dt / N_ITEMS / N_PRODUCERS))
+
 
 main()
diff --git a/examples/shell.py b/examples/shell.py
index f9343256..122091dc 100644
--- a/examples/shell.py
+++ b/examples/shell.py
@@ -1,9 +1,12 @@
 """Examples using create_subprocess_exec() and create_subprocess_shell()."""
 
-import asyncio
+
 import signal
+
+import asyncio
 from asyncio.subprocess import PIPE
 
+
 @asyncio.coroutine
 def cat(loop):
     proc = yield from asyncio.create_subprocess_shell("cat",
@@ -20,6 +23,7 @@ def cat(loop):
     exitcode = yield from proc.wait()
     print("(exit code %s)" % exitcode)
 
+
 @asyncio.coroutine
 def ls(loop):
     proc = yield from asyncio.create_subprocess_exec("ls",
@@ -34,6 +38,7 @@ def ls(loop):
     except ProcessLookupError:
         pass
 
+
 @asyncio.coroutine
 def test_call(*args, timeout=None):
     proc = yield from asyncio.create_subprocess_exec(*args)
@@ -45,6 +50,7 @@ def test_call(*args, timeout=None):
         proc.kill()
         yield from proc.wait()
 
+
 loop = asyncio.get_event_loop()
 loop.run_until_complete(cat(loop))
 loop.run_until_complete(ls(loop))
diff --git a/examples/simple_tcp_server.py b/examples/simple_tcp_server.py
index 5f874ffc..cd403c39 100644
--- a/examples/simple_tcp_server.py
+++ b/examples/simple_tcp_server.py
@@ -9,6 +9,7 @@
 """
 
 import sys
+
 import asyncio
 import asyncio.streams
 
@@ -24,13 +25,13 @@ class MyServer:
     """
 
     def __init__(self):
-        self.server = None # encapsulates the server sockets
+        self.server = None  # encapsulates the server sockets
 
         # this keeps track of all the clients that connected to our
         # server.  It can be useful in some cases, for instance to
         # kill client connections or to broadcast some data to all
         # clients...
-        self.clients = {} # task -> (reader, writer)
+        self.clients = {}  # task -> (reader, writer)
 
     def _accept_client(self, client_reader, client_writer):
         """
@@ -59,7 +60,7 @@ def _handle_client(self, client_reader, client_writer):
         """
         while True:
             data = (yield from client_reader.readline()).decode("utf-8")
-            if not data: # an empty string means the client disconnected
+            if not data:  # an empty string means the client disconnected
                 break
             cmd, *args = data.rstrip().split(' ')
             if cmd == 'add':
@@ -72,7 +73,7 @@ def _handle_client(self, client_reader, client_writer):
                 msg = args[1]
                 client_writer.write("begin\n".encode("utf-8"))
                 for idx in range(times):
-                    client_writer.write("{}. {}\n".format(idx+1, msg)
+                    client_writer.write("{}. {}\n".format(idx + 1, msg)
                                         .encode("utf-8"))
                 client_writer.write("end\n".encode("utf-8"))
             else:
diff --git a/examples/sink.py b/examples/sink.py
index 5d01f9b8..641540f6 100644
--- a/examples/sink.py
+++ b/examples/sink.py
@@ -4,7 +4,8 @@
 import os
 import sys
 
-from asyncio import get_event_loop, coroutine, Protocol
+import asyncio
+
 
 ARGS = argparse.ArgumentParser(description="TCP data sink example.")
 ARGS.add_argument(
@@ -21,7 +22,7 @@
     default=1111, type=int, help='Port number')
 ARGS.add_argument(
     '--maxsize', action='store', dest='maxsize',
-    default=16*1024*1024, type=int, help='Max total data size')
+    default=16 * 1024 * 1024, type=int, help='Max total data size')
 
 server = None
 args = None
@@ -31,7 +32,7 @@ def dprint(*args):
     print('sink:', *args, file=sys.stderr)
 
 
-class Service(Protocol):
+class Service(asyncio.Protocol):
 
     def connection_made(self, tr):
         dprint('connection from', tr.get_extra_info('peername'))
@@ -55,7 +56,7 @@ def connection_lost(self, how):
         dprint('closed', repr(how))
 
 
-@coroutine
+@asyncio.coroutine
 def start(loop, host, port):
     global server
     sslctx = None
@@ -83,7 +84,7 @@ def main():
         loop = ProactorEventLoop()
         set_event_loop(loop)
     else:
-        loop = get_event_loop()
+        loop = asyncio.get_event_loop()
     try:
         loop.run_until_complete(start(loop, args.host, args.port))
     finally:
diff --git a/examples/source.py b/examples/source.py
index 6e5de561..a7c49e85 100644
--- a/examples/source.py
+++ b/examples/source.py
@@ -3,7 +3,7 @@
 import argparse
 import sys
 
-from asyncio import test_utils, get_event_loop, coroutine, Protocol, Future
+import asyncio
 
 
 ARGS = argparse.ArgumentParser(description="TCP data sink example.")
@@ -24,7 +24,7 @@
     default=1111, type=int, help='Port number')
 ARGS.add_argument(
     '--size', action='store', dest='size',
-    default=16*1024, type=int, help='Data size')
+    default=16 * 1024, type=int, help='Data size')
 
 args = None
 
@@ -33,7 +33,7 @@ def dprint(*args):
     print('source:', *args, file=sys.stderr)
 
 
-class Client(Protocol):
+class Client(asyncio.Protocol):
 
     total = 0
 
@@ -42,13 +42,13 @@ def connection_made(self, tr):
         dprint('my socket is', tr.get_extra_info('sockname'))
         self.tr = tr
         self.lost = False
-        self.loop = get_event_loop()
-        self.waiter = Future()
+        self.loop = asyncio.get_event_loop()
+        self.waiter = asyncio.Future()
         if args.stop:
             self.tr.write(b'stop')
             self.tr.close()
         else:
-            self.data = b'x'*args.size
+            self.data = b'x' * args.size
             self.write_some_data()
 
     def write_some_data(self):
@@ -68,11 +68,11 @@ def connection_lost(self, exc):
         self.waiter.set_result(None)
 
 
-@coroutine
+@asyncio.coroutine
 def start(loop, host, port):
     sslctx = None
     if args.tls:
-        sslctx = test_utils.dummy_ssl_context()
+        sslctx = asyncio.test_utils.dummy_ssl_context()
     tr, pr = yield from loop.create_connection(Client, host, port,
                                                ssl=sslctx)
     dprint('tr =', tr)
@@ -88,7 +88,7 @@ def main():
         loop = ProactorEventLoop()
         set_event_loop(loop)
     else:
-        loop = get_event_loop()
+        loop = asyncio.get_event_loop()
     try:
         loop.run_until_complete(start(loop, args.host, args.port))
     finally:
diff --git a/examples/source1.py b/examples/source1.py
index ee52658a..65938cd0 100644
--- a/examples/source1.py
+++ b/examples/source1.py
@@ -3,7 +3,8 @@
 import argparse
 import sys
 
-from asyncio import test_utils, get_event_loop, coroutine, open_connection
+import asyncio
+
 
 ARGS = argparse.ArgumentParser(description="TCP data sink example.")
 ARGS.add_argument(
@@ -23,7 +24,7 @@
     default=1111, type=int, help='Port number')
 ARGS.add_argument(
     '--size', action='store', dest='size',
-    default=16*1024, type=int, help='Data size')
+    default=16 * 1024, type=int, help='Data size')
 
 
 class Debug:
@@ -48,15 +49,15 @@ def oprint(self, *args):
         print(self.label, *args, file=sys.stderr, end=end, flush=True)
 
 
-@coroutine
+@asyncio.coroutine
 def start(loop, args):
     d = Debug()
     total = 0
     sslctx = None
     if args.tls:
         d.print('using dummy SSLContext')
-        sslctx = test_utils.dummy_ssl_context()
-    r, w = yield from open_connection(args.host, args.port, ssl=sslctx)
+        sslctx = asyncio.test_utils.dummy_ssl_context()
+    r, w = yield from asyncio.open_connection(args.host, args.port, ssl=sslctx)
     d.print('r =', r)
     d.print('w =', w)
     if args.stop:
@@ -64,7 +65,7 @@ def start(loop, args):
         w.close()
     else:
         size = args.size
-        data = b'x'*size
+        data = b'x' * size
         try:
             while True:
                 total += size
@@ -86,7 +87,7 @@ def main():
         loop = ProactorEventLoop()
         set_event_loop(loop)
     else:
-        loop = get_event_loop()
+        loop = asyncio.get_event_loop()
     try:
         loop.run_until_complete(start(loop, args))
     finally:
diff --git a/examples/stacks.py b/examples/stacks.py
index ddafa0c6..2c512aa5 100644
--- a/examples/stacks.py
+++ b/examples/stacks.py
@@ -1,28 +1,30 @@
 """Crude demo for print_stack()."""
 
+import asyncio
 
-from asyncio import get_event_loop, open_connection, coroutine, Task, async
 
-
-@coroutine
+@asyncio.coroutine
 def helper(r):
     print('--- helper ---')
-    for t in Task.all_tasks():
+    for t in asyncio.Task.all_tasks():
         t.print_stack()
     print('--- end helper ---')
     line = yield from r.readline()
-    1/0
+    1 / 0
     return line
 
+
 def doit():
-    l = get_event_loop()
+    l = asyncio.get_event_loop()
     lr = l.run_until_complete
-    r, w = lr(open_connection('python.org', 80))
-    t1 = async(helper(r))
-    for t in Task.all_tasks(): t.print_stack()
+    r, w = lr(asyncio.open_connection('python.org', 80))
+    t1 = asyncio.async(helper(r))
+    for t in asyncio.Task.all_tasks():
+        t.print_stack()
     print('---')
     l._run_once()
-    for t in Task.all_tasks(): t.print_stack()
+    for t in asyncio.Task.all_tasks():
+        t.print_stack()
     print('---')
     w.write(b'GET /\r\n')
     w.write_eof()
@@ -31,7 +33,7 @@ def doit():
     except Exception as e:
         print('catching', e)
     finally:
-        for t in Task.all_tasks():
+        for t in asyncio.Task.all_tasks():
             t.print_stack()
     l.close()
 
diff --git a/examples/subprocess_attach_read_pipe.py b/examples/subprocess_attach_read_pipe.py
index d8a62420..918968c3 100644
--- a/examples/subprocess_attach_read_pipe.py
+++ b/examples/subprocess_attach_read_pipe.py
@@ -1,7 +1,10 @@
 #!/usr/bin/env python3
 """Example showing how to attach a read pipe to a subprocess."""
+
+import os
+import sys
+
 import asyncio
-import os, sys
 
 code = """
 import os, sys
@@ -12,6 +15,7 @@
 
 loop = asyncio.get_event_loop()
 
+
 @asyncio.coroutine
 def task():
     rfd, wfd = os.pipe()
@@ -29,5 +33,6 @@ def task():
     data = yield from reader.read()
     print("read = %r" % data.decode())
 
+
 loop.run_until_complete(task())
 loop.close()
diff --git a/examples/subprocess_attach_write_pipe.py b/examples/subprocess_attach_write_pipe.py
index c4e099f6..a3040bca 100644
--- a/examples/subprocess_attach_write_pipe.py
+++ b/examples/subprocess_attach_write_pipe.py
@@ -1,8 +1,10 @@
 #!/usr/bin/env python3
 """Example showing how to attach a write pipe to a subprocess."""
+
+import os
+import sys
+
 import asyncio
-import os, sys
-from asyncio import subprocess
 
 code = """
 import os, sys
@@ -13,6 +15,7 @@
 
 loop = asyncio.get_event_loop()
 
+
 @asyncio.coroutine
 def task():
     rfd, wfd = os.pipe()
@@ -20,7 +23,7 @@ def task():
     proc = yield from asyncio.create_subprocess_exec(
                           *args,
                           pass_fds={rfd},
-                          stdout=subprocess.PIPE)
+                          stdout=asyncio.subprocess.PIPE)
 
     pipe = open(wfd, 'wb', 0)
     transport, _ = yield from loop.connect_write_pipe(asyncio.Protocol,
@@ -31,5 +34,6 @@ def task():
     print("stdout = %r" % stdout.decode())
     transport.close()
 
+
 loop.run_until_complete(task())
 loop.close()
diff --git a/examples/subprocess_shell.py b/examples/subprocess_shell.py
index 745cb646..c09891f9 100644
--- a/examples/subprocess_shell.py
+++ b/examples/subprocess_shell.py
@@ -1,8 +1,9 @@
 """Example writing to and reading from a subprocess at the same time using
 tasks."""
 
-import asyncio
 import os
+
+import asyncio
 from asyncio.subprocess import PIPE
 
 
@@ -23,6 +24,7 @@ def send_input(writer, input):
     except ConnectionResetError:
         print('stdin: connection reset error')
 
+
 @asyncio.coroutine
 def log_errors(reader):
     while True:
@@ -31,6 +33,7 @@ def log_errors(reader):
             break
         print('ERROR', repr(line))
 
+
 @asyncio.coroutine
 def read_stdout(stdout):
     while True:
@@ -39,6 +42,7 @@ def read_stdout(stdout):
         if not line:
             break
 
+
 @asyncio.coroutine
 def start(cmd, input=None, **kwds):
     kwds['stdout'] = PIPE
@@ -79,7 +83,7 @@ def main():
     else:
         loop = asyncio.get_event_loop()
     loop.run_until_complete(start(
-        'sleep 2; wc', input=[b'foo bar baz\n'*300 for i in range(100)]))
+        'sleep 2; wc', input=[b'foo bar baz\n' * 300 for i in range(100)]))
     loop.close()
 
 
diff --git a/examples/tcp_echo.py b/examples/tcp_echo.py
index d743242a..0e11a463 100755
--- a/examples/tcp_echo.py
+++ b/examples/tcp_echo.py
@@ -1,8 +1,12 @@
 #!/usr/bin/env python3
 """TCP echo server example."""
+
 import argparse
-import asyncio
 import sys
+
+import asyncio
+
+
 try:
     import signal
 except ImportError:
diff --git a/examples/timing_tcp_server.py b/examples/timing_tcp_server.py
index 3fcdc974..b3962436 100644
--- a/examples/timing_tcp_server.py
+++ b/examples/timing_tcp_server.py
@@ -27,13 +27,13 @@ class MyServer:
     """
 
     def __init__(self):
-        self.server = None # encapsulates the server sockets
+        self.server = None  # encapsulates the server sockets
 
         # this keeps track of all the clients that connected to our
         # server.  It can be useful in some cases, for instance to
         # kill client connections or to broadcast some data to all
         # clients...
-        self.clients = {} # task -> (reader, writer)
+        self.clients = {}  # task -> (reader, writer)
 
     def _accept_client(self, client_reader, client_writer):
         """
@@ -62,7 +62,7 @@ def _handle_client(self, client_reader, client_writer):
         """
         while True:
             data = (yield from client_reader.readline()).decode("utf-8")
-            if not data: # an empty string means the client disconnected
+            if not data:  # an empty string means the client disconnected
                 break
             cmd, *args = data.rstrip().split(' ')
             if cmd == 'add':
diff --git a/examples/udp_echo.py b/examples/udp_echo.py
index 93ac7e6b..d8f71ed9 100755
--- a/examples/udp_echo.py
+++ b/examples/udp_echo.py
@@ -1,8 +1,12 @@
 #!/usr/bin/env python3
 """UDP echo example."""
+
 import argparse
 import sys
+
 import asyncio
+
+
 try:
     import signal
 except ImportError: