How To Build Scrapy Environment

[Peter Otten]

YetToCome wrote:

> I have already install Twisted, zope.interface, w3lib, libxml2, etc,but it
> still can not be built,here is the error message:
> 
> Traceback (most recent call last):
>   File "C:\Python27\lib\runpy.py", line 162, in _run_module_as_main
>     "__main__", fname, loader, pkg_name)
>   File "C:\Python27\lib\runpy.py", line 72, in _run_code
>     exec code in run_globals
>   File "C:\Python27\lib\site-packages\scrapy\cmdline.py", line 167, in
>   <module>
>     execute()
>   File "C:\Python27\lib\site-packages\scrapy\cmdline.py", line 142, in
>   execute
>     _run_print_help(parser, _run_command, cmd, args, opts)
>   File "C:\Python27\lib\site-packages\scrapy\cmdline.py", line 88, in
>   _run_print
> _help
>     func(*a, **kw)
>   File "C:\Python27\lib\site-packages\scrapy\cmdline.py", line 149, in
>   _run_comm
> and
>     cmd.run(args, opts)
>   File "C:\Python27\lib\site-packages\scrapy\commands\crawl.py", line 47,
>   in run
>     crawler = self.crawler_process.create_crawler()
>   File "C:\Python27\lib\site-packages\scrapy\crawler.py", line 142, in
>   create_cr
> awler
>     self.crawlers[name] = Crawler(self.settings)
>   File "C:\Python27\lib\site-packages\scrapy\crawler.py", line 23, in
>   __init__
>     self.spiders = spman_cls.from_crawler(self)
>   File "C:\Python27\lib\site-packages\scrapy\spidermanager.py", line 35,
>   in from
> _crawler
>     sm = cls.from_settings(crawler.settings)
>   File "C:\Python27\lib\site-packages\scrapy\spidermanager.py", line 31,
>   in from
> _settings
>     return cls(settings.getlist('SPIDER_MODULES'))
>   File "C:\Python27\lib\site-packages\scrapy\spidermanager.py", line 22,
>   in __in
> it__
>     for module in walk_modules(name):
>   File "C:\Python27\lib\site-packages\scrapy\utils\misc.py", line 66, in
>   walk_mo
> dules
>     submod = __import__(fullpath, {}, {}, [''])
>   File "blog_crawl\spiders\dmoz_spider.py", line 1, in <module>
>     class DmozSpider(BaseSpider):
> NameError: name 'BaseSpider' is not defined
> 
> someone tells me why, pls

Assuming you are working your way through the tutorial at

http://doc.scrapy.org/en/latest/intro/tutorial.html#our-first-spider

you probably forgot to import the BaseSpider class with

from scrapy.spider import BaseSpider

as shown in the code snippet in the "Our first Spider" section of the 
tutorial.