欢迎您访问程序员文章站本站旨在为大家提供分享程序员计算机编程知识！
您现在的位置是： 首页

安装python爬虫scrapy踩过的那些坑(转载+整理)

程序员文章站 2022-05-07 23:08:40
...

运行环境：CentOS 6.0

需要软件：python 2.7  pip  scrapy

1、升级python

  • 下载python2.7并安装
#wget https://www.python.org/ftp/python/2.7.10/Python-2.7.10.tgz
#tar -zxvf Python-2.7.10.tgz
#cd Python-2.7.10
#./configure  
#make all             
#make install  
#make clean  
#make distclean
  • 检查python版本
#python --version

发现还是2.6

  • 更改python命令指向
#mv /usr/bin/python /usr/bin/python2.6.6_bak
#ln -s /usr/local/bin/python2.7 /usr/bin/python
  • 再次检查版本
# python --version
Python 2.7.10

到这里，python算是升级完成了，继续安装scrapy。于是pip install scrapy，还是报错。

Collecting Twisted>=10.0.0 (from scrapy)
  Could not find a version that satisfies the requirement Twisted>=10.0.0 (from scrapy) (from versions: )
No matching distribution found for Twisted>=10.0.0 (from scrapy)

少了 Twisted，于是安装 Twisted

2、安装Twisted

  • 下载Twisted（https://pypi.python.org/packages/source/T/Twisted/Twisted-15.2.1.tar.bz2#md5=4be066a899c714e18af1ecfcb01cfef7）
  • 安装
cd Twisted-15.2.1
python setup.py install
  • 查看是否安装成功
python
Python 2.7.10 (default, Jun  5 2015, 17:56:24) 
[GCC 4.4.4 20100726 (Red Hat 4.4.4-13)] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> import twisted
>>>

此时索命twisted已经安装成功。于是继续pip install scrapy，还是报错。

3、安装libxlst、libxml2和xslt-config

Collecting libxlst
  Could not find a version that satisfies the requirement libxlst (from versions: )
No matching distribution found for libxlst
Collecting libxml2
  Could not find a version that satisfies the requirement libxml2 (from versions: )
No matching distribution found for libxml2
wget http://xmlsoft.org/sources/libxslt-1.1.28.tar.gz
cd libxslt-1.1.28/
./configure
make
make install
wget ftp://xmlsoft.org/libxml2/libxml2-git-snapshot.tar.gz
cd libxml2-2.9.2/
./configure
make
make install

安装好以后继续pip install scrapy，幸运之星仍未降临

4、安装cryptography

Failed building wheel for cryptography

下载cryptography（https://pypi.python.org/packages/source/c/cryptography/cryptography-0.4.tar.gz）

安装

cd cryptography-0.4
python setup.py build
python setup.py install

发现安装的时候报错：

No package 'libffi' found

于是下载libffi下载并安装

wget ftp://sourceware.org/pub/libffi/libffi-3.2.1.tar.gz
cd libffi-3.2.1
make
make install

安装后发现仍然报错

Package libffi was not found in the pkg-config search path.
    Perhaps you should add the directory containing `libffi.pc'
    to the PKG_CONFIG_PATH environment variable
    No package 'libffi' found

于是设置：PKG_CONFIG_PATH

export PKG_CONFIG_PATH=/usr/local/lib/pkgconfig:$PKG_CONFIG_PATH

再次安装scrapy

pip install scrapy

幸运女神都去哪儿了？

ImportError: libffi.so.6: cannot open shared object file: No such file or directory

于是

whereis libffi
libffi: /usr/local/lib/libffi.a /usr/local/lib/libffi.la /usr/local/lib/libffi.so
已经正常安装，网上搜索了一通，发现是LD_LIBRARY_PATH没设置，于是
export LD_LIBRARY_PATH=/usr/local/lib

于是继续安装cryptography-0.4

./configure
make
make install

此时正确安装，没有报错信息了。

5、继续安装scrapy

pip install scrapy

看着提示信息：

Building wheels for collected packages: cryptography
  Running setup.py bdist_wheel for cryptography

在这里停了好久，在想幸运女神是不是到了。等了一会

Requirement already satisfied (use --upgrade to upgrade): zope.interface>=3.6.0 in /usr/local/lib/python2.7/site-packages/zope.interface-4.1.2-py2.7-linux-i686.egg (from Twisted>=10.0.0->scrapy)
Collecting cryptography>=0.7 (from pyOpenSSL->scrapy)
  Using cached cryptography-0.9.tar.gz
Requirement already satisfied (use --upgrade to upgrade): setuptools in /usr/local/lib/python2.7/site-packages (from zope.interface>=3.6.0->Twisted>=10.0.0->scrapy)
Requirement already satisfied (use --upgrade to upgrade): idna in /usr/local/lib/python2.7/site-packages (from cryptography>=0.7->pyOpenSSL->scrapy)
Requirement already satisfied (use --upgrade to upgrade): pyasn1 in /usr/local/lib/python2.7/site-packages (from cryptography>=0.7->pyOpenSSL->scrapy)
Requirement already satisfied (use --upgrade to upgrade): enum34 in /usr/local/lib/python2.7/site-packages (from cryptography>=0.7->pyOpenSSL->scrapy)
Requirement already satisfied (use --upgrade to upgrade): ipaddress in /usr/local/lib/python2.7/site-packages (from cryptography>=0.7->pyOpenSSL->scrapy)
Requirement already satisfied (use --upgrade to upgrade): cffi>=0.8 in /usr/local/lib/python2.7/site-packages (from cryptography>=0.7->pyOpenSSL->scrapy)
Requirement already satisfied (use --upgrade to upgrade): ordereddict in /usr/local/lib/python2.7/site-packages (from enum34->cryptography>=0.7->pyOpenSSL->scrapy)
Requirement already satisfied (use --upgrade to upgrade): pycparser in /usr/local/lib/python2.7/site-packages (from cffi>=0.8->cryptography>=0.7->pyOpenSSL->scrapy)
Building wheels for collected packages: cryptography
  Running setup.py bdist_wheel for cryptography
  Stored in directory: /root/.cache/pip/wheels/d7/64/02/7258f08eae0b9c930c04209959c9a0794b9729c2b64258117e
Successfully built cryptography
Installing collected packages: cryptography
  Found existing installation: cryptography 0.4
    Uninstalling cryptography-0.4:
      Successfully uninstalled cryptography-0.4
Successfully installed cryptography-0.9

显示如此的信息。看到此刻，内流马面。谢谢CCAV，感谢MTV，钓鱼岛是中国的。终于安装成功了。

6、测试scrapy

创建测试脚本

cat > myspider.py <<EOF
from scrapy import Spider, Item, Field
class Post(Item):
  title = Field()
class BlogSpider(Spider):
  name, start_urls = 'blogspider', ['http://www.cnblogs.com/rwxwsblog/']
  def parse(self, response):
    return [Post(title=e.extract()) for e in response.css("h2 a::text")]
EOF

 

测试脚本能否正常运行

scrapy runspider myspider.py
2015-06-06 20:25:16 [scrapy] INFO: Scrapy 1.0.0rc2 started (bot: scrapybot)
2015-06-06 20:25:16 [scrapy] INFO: Optional features available: ssl, http11
2015-06-06 20:25:16 [scrapy] INFO: Overridden settings: {}
2015-06-06 20:25:16 [py.warnings] WARNING: :0: UserWarning: You do not have a working installation of the service_identity module: 'No module named service_identity'.  Please install it from <https://pypi.python.org/pypi/service_identity> and make sure all of its dependencies are satisfied.  Without the service_identity module and a recent enough pyOpenSSL to support it, Twisted can perform only rudimentary TLS client hostname verification.  Many valid certificate/hostname mappings may be rejected.

2015-06-06 20:25:16 [scrapy] INFO: Enabled extensions: CloseSpider, TelnetConsole, LogStats, CoreStats, SpiderState
2015-06-06 20:25:16 [scrapy] INFO: Enabled downloader middlewares: HttpAuthMiddleware, DownloadTimeoutMiddleware, UserAgentMiddleware, RetryMiddleware, DefaultHeadersMiddleware, MetaRefreshMiddleware, HttpCompressionMiddleware, RedirectMiddleware, CookiesMiddleware, ChunkedTransferMiddleware, DownloaderStats
2015-06-06 20:25:16 [scrapy] INFO: Enabled spider middlewares: HttpErrorMiddleware, OffsiteMiddleware, RefererMiddleware, UrlLengthMiddleware, DepthMiddleware
2015-06-06 20:25:16 [scrapy] INFO: Enabled item pipelines: 
2015-06-06 20:25:16 [scrapy] INFO: Spider opened
2015-06-06 20:25:16 [scrapy] INFO: Crawled 0 pages (at 0 pages/min), scraped 0 items (at 0 items/min)
2015-06-06 20:25:16 [scrapy] DEBUG: Telnet console listening on 127.0.0.1:6023
2015-06-06 20:25:17 [scrapy] DEBUG: Crawled (200) <GET http://www.cnblogs.com/rwxwsblog/> (referer: None)
2015-06-06 20:25:17 [scrapy] INFO: Closing spider (finished)
2015-06-06 20:25:17 [scrapy] INFO: Dumping Scrapy stats:
{'downloader/request_bytes': 226,
 'downloader/request_count': 1,
 'downloader/request_method_count/GET': 1,
 'downloader/response_bytes': 5383,
 'downloader/response_count': 1,
 'downloader/response_status_count/200': 1,
 'finish_reason': 'finished',
 'finish_time': datetime.datetime(2015, 6, 6, 12, 25, 17, 310084),
 'log_count/DEBUG': 2,
 'log_count/INFO': 7,
 'log_count/WARNING': 1,
 'response_received_count': 1,
 'scheduler/dequeued': 1,
 'scheduler/dequeued/memory': 1,
 'scheduler/enqueued': 1,
 'scheduler/enqueued/memory': 1,
 'start_time': datetime.datetime(2015, 6, 6, 12, 25, 16, 863599)}
2015-06-06 20:25:17 [scrapy] INFO: Spider closed (finished)
运行正常（此时心中窃喜，^_^....）。

7、创建自己的scrapy项目（此时换了一个会话）

scrapy startproject tutorial

输出以下信息

Traceback (most recent call last):
  File "/usr/local/bin/scrapy", line 9, in <module>
    load_entry_point('Scrapy==1.0.0rc2', 'console_scripts', 'scrapy')()
  File "/usr/local/lib/python2.7/site-packages/pkg_resources/__init__.py", line 552, in load_entry_point
    return get_distribution(dist).load_entry_point(group, name)
  File "/usr/local/lib/python2.7/site-packages/pkg_resources/__init__.py", line 2672, in load_entry_point
    return ep.load()
  File "/usr/local/lib/python2.7/site-packages/pkg_resources/__init__.py", line 2345, in load
    return self.resolve()
  File "/usr/local/lib/python2.7/site-packages/pkg_resources/__init__.py", line 2351, in resolve
    module = __import__(self.module_name, fromlist=['__name__'], level=0)
  File "/usr/local/lib/python2.7/site-packages/Scrapy-1.0.0rc2-py2.7.egg/scrapy/__init__.py", line 48, in <module>
    from scrapy.spiders import Spider
  File "/usr/local/lib/python2.7/site-packages/Scrapy-1.0.0rc2-py2.7.egg/scrapy/spiders/__init__.py", line 10, in <module>
    from scrapy.http import Request
  File "/usr/local/lib/python2.7/site-packages/Scrapy-1.0.0rc2-py2.7.egg/scrapy/http/__init__.py", line 11, in <module>
    from scrapy.http.request.form import FormRequest
  File "/usr/local/lib/python2.7/site-packages/Scrapy-1.0.0rc2-py2.7.egg/scrapy/http/request/form.py", line 9, in <module>
    import lxml.html
  File "/usr/local/lib/python2.7/site-packages/lxml/html/__init__.py", line 42, in <module>
    from lxml import etree
ImportError: /usr/lib/libxml2.so.2: version `LIBXML2_2.9.0' not found (required by /usr/local/lib/python2.7/site-packages/lxml/etree.so)
心中无数个*再次狂奔。怎么又不行了？难道会变戏法？定定神看了下：ImportError: /usr/lib/libxml2.so.2: version `LIBXML2_2.9.0' not found (required by /usr/local/lib/python2.7/site-packages/lxml/etree.so)。这是那样的熟悉呀！想了想，这怎么和前面的ImportError: libffi.so.6: cannot open shared object file: No such file or directory那么类似呢？于是

8、添加环境变量

export LD_LIBRARY_PATH=/usr/local/lib

再次运行：

scrapy startproject tutorial

输出以下信息：

[[email protected] scrapy]# scrapy startproject tutorial
2015-06-06 20:35:43 [scrapy] INFO: Scrapy 1.0.0rc2 started (bot: scrapybot)
2015-06-06 20:35:43 [scrapy] INFO: Optional features available: ssl, http11
2015-06-06 20:35:43 [scrapy] INFO: Overridden settings: {}
New Scrapy project 'tutorial' created in:
    /root/scrapy/tutorial

You can start your first spider with:
    cd tutorial
    scrapy genspider example example.com

尼玛的终于成功了。由此可见，scrapy运行的时候需要 LD_LIBRARY_PATH 环境变量的支持。可以考虑将其加入环境变量中

vi /etc/profile

添加：export LD_LIBRARY_PATH=/usr/local/lib 这行（前面的PKG_CONFIG_PATH也可以考虑添加进来，export PKG_CONFIG_PATH=/usr/local/lib/pkgconfig:$PKG_CONFIG_PATH）

保存后检查是否存在异常：

source /etc/profile

开一个新的会话运行

scrapy runspider myspider.py

发现正常运行，可见LD_LIBRARY_PATH是生效的。至此scrapy就算正式安装成功了。

查看scrapy版本：运行scrapy version，看了下scrapy的版本为“Scrapy 1.0.0rc2”

9、problems with python 2.7 on Centeros whith sqlite3 module

ln -s /usr/lib64/python2.6/lib-dynload/_sqlite3.so /usr/local/lib/python2.7/lib-dynload/

 

10、参考文档

http://scrapy.org/

http://doc.scrapy.org/en/master/

http://blog.csdn.net/slvher/article/details/42346887

http://blog.csdn.net/niying/article/details/27103081

http://www.cnblogs.com/xiaoruoen/archive/2013/02/27/2933854.html

 

 

 

http://mongodb.github.io/node-mongodb-native/api-generated/

 

http://www.tuicool.com/topics/11020113

http://api.mongodb.com/python/current/tutorial.html?_ga=1.121639885.739648235.1464769227

 

上一篇： python爬虫之xpath案例——全国城市名称爬取

下一篇： Python爬虫学习第三章-4.1.1-xpath解析概述

推荐阅读