我正在尝试在http://eventlet.net/doc/examples.html，webcrawler.py上运行第一个代码示例：
#!/usr/bin/env python
"""
This is a simple web "crawler" that fetches a bunch of urls using a pool to
control the number of outbound connections. It has as many simultaneously open
connections as coroutines in the pool.
The prints in the body of the fetch function are there to demonstrate that the
requests are truly made in parallel.
"""
import eventlet
from eventlet.green import urllib2
urls = [
"https://www.google.com/intl/en_ALL/images/logo.gif",
"http://python.org/images/python-logo.gif",
"http://us.i1.yimg.com/us.yimg.com/i/ww/beta/y3.gif",
]
def fetch(url):
print("opening", url)
body = urllib2.urlopen(url).read()
print("done with", url)
return url, body
pool = eventlet.GreenPool(200)
for url, body in pool.imap(fetch, urls):
print("got body from", url, "of length", len(body))
但是，这导致
ModuleNotFoundError: No module named 'urllib2'
我正在使用eventlet版本0.21.0。此模块是否已在eventlet中移动？
最佳答案
最后，我将构建系统（在Sublime Editor中）切换为Python 2而不是Python3。现在它可以按预期运行：
('opening', 'https://www.google.com/intl/en_ALL/images/logo.gif')
('opening', 'http://python.org/images/python-logo.gif')
('opening', 'http://us.i1.yimg.com/us.yimg.com/i/ww/beta/y3.gif')
('done with', 'https://www.google.com/intl/en_ALL/images/logo.gif')
('got body from', 'https://www.google.com/intl/en_ALL/images/logo.gif', 'of length', 8558)
('done with', 'http://us.i1.yimg.com/us.yimg.com/i/ww/beta/y3.gif')
('done with', 'http://python.org/images/python-logo.gif')
('got body from', 'http://python.org/images/python-logo.gif', 'of length', 2549)
('got body from', 'http://us.i1.yimg.com/us.yimg.com/i/ww/beta/y3.gif', 'of length', 1874)
[Finished in 0.8s]
顺便说一句，这表明绿色线程按预期异步运行。
关于python - 找不到eventlet.green.urllib2模块，我们在Stack Overflow上找到一个类似的问题：https://stackoverflow.com/questions/47171621/