python基礎-執行緒建立、執行緒池、進\執行緒非同步回撥(add_done_callback)、進\執行緒資料共享、ftp執行緒池
阿新 • • 發佈:2019-02-07
執行緒建立
程序只是用來把資源集中到一起(程序只是一個資源單位,或者說資源集合),而執行緒才是cpu上的執行單位。
每個程序有一個地址空間,而且預設就有一個控制執行緒
執行緒就是一條流水線工作的過程,一條流水線必須屬於一個車間,一個車間的工作過程是一個程序
多執行緒(即多個控制執行緒)的概念是,在一個程序中存在多個控制執行緒,多個控制執行緒共享該程序的地址空間,相當於一個車間內有多條流水線,都共用一個車間的資源
我們之前瞭解過程序的2種建立方式
下面的程式碼是2種建立執行緒的方式
from threading import Thread
from multiprocessing import Process
import time,os
def task():
print('%s is running' %os.getpid())
time.sleep(2)
print('%s is done' %os.getpid())
class Mythread(Thread):
def __init__(self,name):
super().__init__()
self.name=name
def run(self):
print('%s is running' % os.getpid())
time.sleep(5 )
print('%s is done' % os.getpid())
if __name__ == '__main__':
t=Thread(target=task)
# t=Mythread('xxxxx')
t.start()
print('主')
輸出如下:
E:\python\python_sdk\python.exe "E:/python/py_pro/1 開啟執行緒的兩種方式.py"
10336 is running
主
10336 is done
Process finished with exit code 0
執行緒程序pid
part1:在主程序下開啟多個執行緒,每個執行緒都跟主程序的pid一樣
from threading import Thread
from multiprocessing import Process
import time,os
def task():
print('partent:%s self:%s' %(os.getppid(),os.getpid()))
time.sleep(5)
if __name__ == '__main__':
t=Thread(target=task,)
# t=Process(target=task,)
t.start()
print('主',os.getppid(),os.getpid())
輸出如下:
partent:9052 self:10120
主 9052 10120
開多個程序,每個程序都有不同的pid
from threading import Thread
from multiprocessing import Process
import time,os
def task():
print('partent:%s self:%s' %(os.getppid(),os.getpid()))
time.sleep(5)
if __name__ == '__main__':
t=Process(target=task,)
t.start()
print('主',os.getppid(),os.getpid())
輸出如下:
主 9052 2668
partent:2668 self:8744
執行緒程序資料共享
程序之間資料不共享,但是程序之間可以通過ipc進行資料通訊
from threading import Thread
from multiprocessing import Process
import time,os
n=100
def task():
global n
n=0
if __name__ == '__main__':
t=Process(target=task,)
t.start()
t.join()
print('主',n)
輸出如下:
主 100
執行緒之間記憶體空間共享
from threading import Thread
import time,os
n=100
def task():
global n
n=0
if __name__ == '__main__':
t=Thread(target=task,)
t.start()
t.join()
print('主',n)
輸出如下:
主 0
執行緒ftp
服務端:
import multiprocessing
import threading
import socket
s=socket.socket(socket.AF_INET,socket.SOCK_STREAM)
s.bind(('127.0.0.1',8081))
s.listen(5)
def action(conn):
while True:
data=conn.recv(1024)
print(data)
conn.send(data.upper())
if __name__ == '__main__':
while True:
conn,addr=s.accept()
p=threading.Thread(target=action,args=(conn,))
p.start()
客戶端:
from socket import *
client=socket(AF_INET,SOCK_STREAM)
client.connect(('127.0.0.1',8081))
while True:
msg=input('>>: ').strip()
if not msg:continue
client.send(msg.encode('utf-8'))
msg=client.recv(1024)
print(msg.decode('utf-8'))
執行緒池
from concurrent.futures import ProcessPoolExecutor,ThreadPoolExecutor
from threading import current_thread
import time,random
def task(n):
print('%s is running' %current_thread().getName())
time.sleep(random.randint(1,3))
return n**2
if __name__ == '__main__':
t=ThreadPoolExecutor(3) #預設是cpu的核數*5
objs=[]
for i in range(5):
obj=t.submit(task,i)
objs.append(obj)
t.shutdown(wait=True)
for obj in objs:
print(obj.result())
print('主',current_thread().getName())
輸出如下:
E:\python\python_sdk\python.exe "E:/python/py_pro/4 執行緒池.py"
ThreadPoolExecutor-0_0 is running
ThreadPoolExecutor-0_1 is running
ThreadPoolExecutor-0_2 is running
ThreadPoolExecutor-0_0 is running
ThreadPoolExecutor-0_1 is running
0
1
4
9
16
主 MainThread
執行緒池ftp
服務端:
from socket import *
from concurrent.futures import ThreadPoolExecutor
import os
server=socket(AF_INET,SOCK_STREAM)
server.setsockopt(SOL_SOCKET,SO_REUSEADDR,1)
server.bind(('127.0.0.1',8080))
server.listen(5)
def talk(conn,client_addr):
print('程序pid: %s' %os.getpid())
while True:
try:
msg=conn.recv(1024)
if not msg:break
conn.send(msg.upper())
except Exception:
break
if __name__ == '__main__':
p=ThreadPoolExecutor(5)
while True:
conn,client_addr=server.accept()
p.submit(talk,conn,client_addr)
客戶端:
from socket import *
client=socket(AF_INET,SOCK_STREAM)
client.connect(('127.0.0.1',8081))
while True:
msg=input('>>: ').strip()
if not msg:continue
client.send(msg.encode('utf-8'))
msg=client.recv(1024)
print(msg.decode('utf-8'))
執行緒的一些其他方法
from threading import Thread,current_thread,enumerate,active_count
import time,os
def task():
print('%s is running' %current_thread().getName())
time.sleep(5)
print('%s is done' %current_thread().getName())
if __name__ == '__main__':
t=Thread(target=task,name='xxxx')
t.start()
print(t.name)
#檢視當前活著的執行緒
print(enumerate()[0].getName())
print(active_count())
print('主',current_thread().getName())
print()
輸出如下:
E:\python\python_sdk\python.exe "E:/python/py_pro/3 執行緒物件的其他屬性或方法.py"
xxxx is running
xxxx
MainThread
2
主 MainThread
xxxx is done
非同步-回撥函式
ProcessPoolExecutor方式
我們之前總結的非同步返回結果沒有用到呼叫函式,接下來的是利用了回撥函式
#pip install requests
import requests
from concurrent.futures import ThreadPoolExecutor,ProcessPoolExecutor
from threading import current_thread
import time,os
def get(url):
print('%s GET %s' %(os.getpid(),url))
response=requests.get(url)
time.sleep(3)
if response.status_code == 200:
return {'url':url,'text':response.text}
def parse(obj):
res=obj.result()
print('[%s] <%s> (%s)' % (os.getpid(), res['url'],len(res['text'])))
if __name__ == '__main__':
urls = [
'https://www.python.org',
'https://www.baidu.com',
'https://www.jd.com',
'https://www.tmall.com',
]
t=ProcessPoolExecutor(2)
for url in urls:
t.submit(get,url).add_done_callback(parse)
t.shutdown(wait=True)
print('主',os.getpid())
程式碼思路是:
t=ProcessPoolExecutor(2)開一個程序池,然後去併發下載網路資料,下載完畢後,
在主程序中add_done_callback去解析
這裡由於主程序、子程序不是同一個程序空間,所以在解析資料時候,在主程序
輸出如下:
E:\python\python_sdk\python.exe "E:/python/py_pro/5 補充非同步的概念.py"
5628 GET https://www.python.org
4816 GET https://www.baidu.com
4816 GET https://www.jd.com
[3204] <https://www.baidu.com> (2443)
[3204] <https://www.python.org> (48856)
5628 GET https://www.tmall.com
[3204] <https://www.jd.com> (124541)
[3204] <https://www.tmall.com> (212080)
主 3204
Process finished with exit code 0
ThreadPoolExecutor方式
import requests
from concurrent.futures import ThreadPoolExecutor,ProcessPoolExecutor
from threading import current_thread
import time
import os
def get(url):
print('%s GET %s,%s' %(current_thread().getName(),os.getpid(),url))
response=requests.get(url)
time.sleep(3)
if response.status_code == 200:
return {'url':url,'text':response.text}
def parse(obj):
res=obj.result()
print('[%s] <%s> (%s)' % (current_thread().getName(), res['url'],len(res['text'])))
if __name__ == '__main__':
urls = [
'https://www.python.org',
'https://www.baidu.com',
'https://www.jd.com',
'https://www.tmall.com',
]
t=ThreadPoolExecutor(2)
for url in urls:
t.submit(get,url).add_done_callback(parse)
t.shutdown(wait=True)
print('主',current_thread().getName(),os.getpid())
程式碼思路是:
t=ThreadPoolExecutor(2)開一個執行緒池,然後去併發下載網路資料,下載完畢後,
在主執行緒程中add_done_callback去解析
這裡由於主執行緒、子執行緒是同一個程序空間,所以在解析資料時候,可能主執行緒、子執行緒都會解析
輸出如下:
E:\python\python_sdk\python.exe "E:/python/py_pro/5 補充非同步的概念.py"
ThreadPoolExecutor-0_0 GET 12956,https://www.python.org
ThreadPoolExecutor-0_1 GET 12956,https://www.baidu.com
[ThreadPoolExecutor-0_1] <https://www.baidu.com> (2443)
ThreadPoolExecutor-0_1 GET 12956,https://www.jd.com
[ThreadPoolExecutor-0_0] <https://www.python.org> (48856)
ThreadPoolExecutor-0_0 GET 12956,https://www.tmall.com
[ThreadPoolExecutor-0_1] <https://www.jd.com> (124541)
[ThreadPoolExecutor-0_0] <https://www.tmall.com> (212079)
主 MainThread 12956
Process finished with exit code 0