发出HTTP请求时，Python子进程默默崩溃 [英] Python child process silently crashes when issuing an HTTP request
问题描述
在将多重处理，请求(或urllib2)和nltk结合在一起时，我遇到了一个问题.这是一个非常简单的代码:
I'm running into an issue when combining multiprocessing, requests (or urllib2) and nltk. Here is a very simple code:
>>> from multiprocessing import Process
>>> import requests
>>> from pprint import pprint
>>> Process(target=lambda: pprint(
requests.get('https://api.github.com'))).start()
>>> <Response [200]> # this is the response displayed by the call to `pprint`.
有关这段代码的作用的更多详细信息:
A bit more details on what this piece of code does:
- 导入一些必需的模块
- 启动子进程
- 从子进程向"api.github.com"发出HTTP GET请求
- 显示结果
这很好.导入nltk时出现问题:
This is working great. The problem comes when importing nltk:
>>> import nltk
>>> Process(target=lambda: pprint(
requests.get('https://api.github.com'))).start()
>>> # nothing happens!
导入了NLTK之后，请求实际上实际上使线程崩溃(如果尝试使用命名函数而不是lambda函数，在调用之前和之后添加一些print语句，您将看到执行停止就在呼叫requests.get的位置)
是否有人知道NLTK中的什么可以解释这种行为以及如何克服该问题?
After having imported NLTK, the requests actually silently crashes the thread (if you try with a named function instead of the lambda function, adding a few print statement before and after the call, you'll see that the execution stops right on the call to requests.get)
Does anybody have any idea what in NLTK could explain such behavior, and how to get overcome the issue?
这是我使用的版本:
$> python --version
Python 2.7.5
$> pip freeze | grep nltk
nltk==2.0.5
$> pip freeze | grep requests
requests==2.2.1
我正在运行Mac OS X 10.9.5版.
I'm running Mac OS X v. 10.9.5.
谢谢！
推荐答案
更新python库和python应该可以解决问题:
Updating your python libraries and python should resolve the problem:
alvas@ubi:~$ pip freeze | grep nltk
nltk==3.0.3
alvas@ubi:~$ pip freeze | grep requests
requests==2.7.0
alvas@ubi:~$ python --version
Python 2.7.6
alvas@ubi:~$ lsb_release -a
No LSB modules are available.
Distributor ID: Ubuntu
Description: Ubuntu 14.04.2 LTS
Release: 14.04
Codename: trusty
来自代码:
from multiprocessing import Process
import nltk
import time
def child_fn():
print "Fetch URL"
import urllib2
print urllib2.urlopen("https://www.google.com").read()[:100]
print "Done"
while True:
child_process = Process(target=child_fn)
child_process.start()
child_process.join()
print "Child process returned"
time.sleep(1)
[输出]:
Fetch URL
<!doctype html><html itemscope="" itemtype="http://schema.org/WebPage" lang="de"><head><meta content
Done
Child process returned
Fetch URL
<!doctype html><html itemscope="" itemtype="http://schema.org/WebPage" lang="de"><head><meta content
Done
Child process returned
Fetch URL
<!doctype html><html itemscope="" itemtype="http://schema.org/WebPage" lang="de"><head><meta content
Done
Child process returned
来自代码:
alvas@ubi:~$ python
Python 2.7.6 (default, Jun 22 2015, 17:58:13)
[GCC 4.8.2] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> from multiprocessing import Process
>>> import requests
>>> from pprint import pprint
>>> Process(target=lambda: pprint(
... requests.get('https://api.github.com'))).start()
>>> <Response [200]>
>>> import nltk
>>> Process(target=lambda: pprint(
... requests.get('https://api.github.com'))).start()
>>> <Response [200]>
它也应该与python3一起使用:
It should work with python3 too:
alvas@ubi:~$ python3
Python 3.4.0 (default, Jun 19 2015, 14:20:21)
[GCC 4.8.2] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> from multiprocessing import Process
>>> import requests
>>> Process(target=lambda: print(requests.get('https://api.github.com'))).start()
>>>
>>> <Response [200]>
>>> import nltk
>>> Process(target=lambda: print(requests.get('https://api.github.com'))).start()
>>> <Response [200]>
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