您可以使用选择器来处理I/O多路复用:
https://docs.python.org/zh-cn/3/library/selectors.html
请尝试这个:
import sys
import fcntl
import os
import selectors
orig_fl = fcntl.fcntl(sys.stdin, fcntl.F_GETFL)
fcntl.fcntl(sys.stdin, fcntl.F_SETFL, orig_fl | os.O_NONBLOCK)
def got_keyboard_data(stdin):
print('Keyboard input: {}'.format(stdin.read()))
m_selector = selectors.DefaultSelector()
m_selector.register(sys.stdin, selectors.EVENT_READ, got_keyboard_data)
while True:
sys.stdout.write('Type something and hit enter: ')
sys.stdout.flush()
for k, mask in m_selector.select():
callback = k.data
callback(k.fileobj)
以上代码将会在该行停留。
for k, mask in m_selector.select():
直到发生已注册的事件,才返回一个选择器键实例(k)和所监控事件的掩码。
在上面的示例中,我们仅注册了一个事件(Enter键按下)。
m_selector.register(sys.stdin, selectors.EVENT_READ, got_keyboard_data)
选择器键实例的定义如下:
abstractmethod register(fileobj, events, data=None)
因此,register方法将
k.data
设置为我们的回调函数
got_keyboard_data
,并在按下
Enter键时调用它:
callback = k.data
callback(k.fileobj)
一个更完整(并且希望更有用)的例子是将用户的 stdin 数据与来自网络的传入连接进行多路复用:
import selectors
import socket
import sys
import os
import fcntl
m_selector = selectors.DefaultSelector()
def set_input_nonblocking():
orig_fl = fcntl.fcntl(sys.stdin, fcntl.F_GETFL)
fcntl.fcntl(sys.stdin, fcntl.F_SETFL, orig_fl | os.O_NONBLOCK)
def create_socket(port, max_conn):
server_addr = ('localhost', port)
server = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
server.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
server.setblocking(False)
server.bind(server_addr)
server.listen(max_conn)
return server
def read(conn, mask):
global GO_ON
client_address = conn.getpeername()
data = conn.recv(1024)
print('Got {} from {}'.format(data, client_address))
if not data:
GO_ON = False
def accept(sock, mask):
new_conn, addr = sock.accept()
new_conn.setblocking(False)
print('Accepting connection from {}'.format(addr))
m_selector.register(new_conn, selectors.EVENT_READ, read)
def quit():
global GO_ON
print('Exiting...')
GO_ON = False
def from_keyboard(arg1, arg2):
line = arg1.read()
if line == 'quit\n':
quit()
else:
print('User input: {}'.format(line))
GO_ON = True
set_input_nonblocking()
server = create_socket(10000, 10)
m_selector.register(server, selectors.EVENT_READ, accept)
m_selector.register(sys.stdin, selectors.EVENT_READ, from_keyboard)
while GO_ON:
sys.stdout.write('>>> ')
sys.stdout.flush()
for k, mask in m_selector.select():
callback = k.data
callback(k.fileobj, mask)
m_selector.unregister(sys.stdin)
server.shutdown()
server.close()
m_selector.close()
你可以使用两个终端进行测试。
第一个终端:
$ python3 test.py
>>> bla
打开另一个终端并运行:
$ nc localhost 10000
hey!
回到第一个
>>> qwerqwer
结果(显示在主终端上):
$ python3 test.py
>>> bla
User input: bla
>>> Accepting connection from ('127.0.0.1', 39598)
>>> Got b'hey!\n' from ('127.0.0.1', 39598)
>>> qwerqwer
User input: qwerqwer
>>>