进度条的打印
import sys,time
for i in range(20):
sys.stdout.write('$') #stdout是标准输出的意思,在一般电脑上,stdout的标准输出指的是计算机屏幕。
sys.stdout.flush()
time.sleep(0.1)
单线程下的并发运算:
import time def consumer(name): print("%s 准备吃包子啦!" %name) while True: baozi = yield print("包子[%s]来了,被[%s]吃了!" %(baozi,name))
def producer(name): c = consumer('A') c2 = consumer('B') c.__next__() c2.__next__() print("老子开始准备做包子啦!") for i in range(10): time.sleep(1) print("做了2个包子!") c.send(i) c2.send(i) producer("gavin")
生成数字+字母的验证码的小程序
__author__ = "Gavin"
import random
checkcode=''
for i in range(5):
current=random.randrange(0,5)
if current == i:
tmp=chr(random.randint(65,90))
else:
tmp=random.randint(0,9)
checkcode+=str(tmp)
print(checkcode)
异步I/O写的SocketServer
使用协程的方式,执行效率极高
server side
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import sys import socket import time import gevent from gevent import socket,monkey monkey.patch_all() def server(port): s = socket.socket() s.bind(( '0.0.0.0' , port)) s.listen( 500 ) while True : cli, addr = s.accept() gevent.spawn(handle_request, cli) def handle_request(conn): try : while True : data = conn.recv( 1024 ) print ( "recv:" , data) conn.send(data) if not data: conn.shutdown(socket.SHUT_WR) except Exception as ex: print (ex) finally : conn.close() if __name__ = = '__main__' : server( 8001 ) |
client side
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import socket HOST = 'localhost' # The remote host PORT = 8001 # The same port as used by the server s = socket.socket(socket.AF_INET, socket.SOCK_STREAM) s.connect((HOST, PORT)) while True : msg = bytes( input ( ">>:" ),encoding = "utf8" ) s.sendall(msg) data = s.recv( 1024 ) #print(data) print ( 'Received' , repr (data)) s.close() |