python - scrapy无法初始化项目

Question

在交互环境

import scrapy    # 成功

但是在终端 scrapy 新建项目就出错了

Traceback (most recent call last):
  File "/usr/local/bin/scrapy", line 7, in <module>
    from scrapy.cmdline import execute
  File "/usr/local/lib/python2.7/dist-packages/scrapy/cmdline.py", line 9, in <module>
    from scrapy.crawler import CrawlerProcess
  File "/usr/local/lib/python2.7/dist-packages/scrapy/crawler.py", line 15, in <module>
    from scrapy.signalmanager import SignalManager
  File "/usr/local/lib/python2.7/dist-packages/scrapy/signalmanager.py", line 2, in <module>
    from pydispatch import dispatcher
ImportError: No module named pydispatch

可是, pydispatch包已经有了呀!

$ pip install --upgrade pydispatch

Requirement already up-to-date: pydispatch in /usr/local/lib/python2.7/dist-packages
Requirement already up-to-date: colorama>=0.2.7 in /usr/local/lib/python2.7/dist-packages (from pydispatch)
Requirement already up-to-date: six>=1.5.2 in /usr/local/lib/python2.7/dist-packages (from pydispatch)

Answer 1

是否環境搭建的有問題？
在你出問題的程式碼中check一下安裝包有沒有：

>>> import pip
>>> installed_packages = pip.get_installed_distributions()
>>> installed_packages_list = sorted(["%s==%s" % (i.key, i.version)
...      for i in installed_packages])
>>> print(installed_packages_list)

方法取自：
http://stackoverflow.com/questions/739993/how-can-i-get-a-list-of-locally-installed-python-modules

Answer 2

我查了下Scrapy的 Release notes,發現

The previously bundled scrapy.xlib.pydispatch library was deprecated and replaced by pydispatcher.

也就是說最新版本的scrapy是沒有用到pydispatch 模組的,用的是pydispatcher 模組
所以可能你用的不是最新的scrapy?
解決方法的話,我建議你用virtualenv搭建一個獨立的python環境,在這個環境下重新安裝最新的scrapy.
或直接在系統裡重新安裝scrapy

Answer 3

pip 安裝 PyDispatcher