Question

import tornado.ioloop
import tornado.iostream
import socket

def send_request():
    stream.write(b"GET / HTTP/1.0\r\nHost: friendfeed.com\r\n\r\n")
    stream.read_until(b"\r\n\r\n", on_headers)

def on_headers(data):
    headers = {}
    for line in data.split(b"\r\n"):
       parts = line.split(b":")
       if len(parts) == 2:
           headers[parts[0].strip()] = parts[1].strip()
    stream.read_bytes(int(headers[b"Content-Length"]), on_body)

def on_body(data):
    print(data)
    stream.close()
    tornado.ioloop.IOLoop.current().stop()

if __name__ == '__main__':
    s = socket.socket(socket.AF_INET, socket.SOCK_STREAM, 0)
    stream = tornado.iostream.IOStream(s)
    stream.connect(("friendfeed.com", 80), send_request)
    tornado.ioloop.IOLoop.current().start()

http://www.tornadoweb.org/en/stable/iostream.html

这是来自python tornado文档的演示代码，然后我做了一点改动：

#!/usr/bin/env python
# -*- coding:utf-8 -*-

import tornado.ioloop
import tornado.iostream
import socket

def send_request():
    stream.write(b"GET / HTTP/1.0\r\nHost: friendfeed.com\r\n\r\n")
    stream.read_until(b"\r\n\r\n", on_headers)

def on_headers(data):
    headers = {}
    for line in data.split(b"\r\n"):
       parts = line.split(b":")
       if len(parts) == 2:
           headers[parts[0].strip()] = parts[1].strip()
    stream.read_bytes(int(headers[b"Content-Length"]), on_body)

def on_body(data):
    print(data)
    stream.close()
    tornado.ioloop.IOLoop.current().stop()

def main():
    s = socket.socket(socket.AF_INET, socket.SOCK_STREAM, 0)
    stream = tornado.iostream.IOStream(s)
    stream.connect(("friendfeed.com", 80), send_request)
    tornado.ioloop.IOLoop.current().start()

if __name__ == '__main__':
    main()

我只是将最后四个语句移动到一个main函数，然后我错过了一个错误＆＃34; NameError：name＆＃39; stream＆＃39;未定义＆＃34;。那么它们之间的区别是什么？感谢。

Answer 1

您需要将stream对象定义为全局，因为其他函数使用它。

实施例

def g():
    global stream
    stream = 4*x
    print stream

def f():
    global x
    x = 4
    print x

f()
g()

这会打印两个变量而不会出错。

因此，请使用

def main():
    global stream
    . . .

龙卷风演示代码，NameError：name＆＃39; stream＆＃39;没有定义

1 个答案: