python-1.Centos7安装Python3.6和Scrapy的方法

由于centos7原本就安装了Python2，而且这个Python2不能被删除，因为有很多系统命令，比如yum都要用到

[root@iZm5efjrz9szlsq1a0ai3gZ ~]# python
Python 2.7.5 (default, Jun 20 2019, 20:27:34) 
[GCC 4.8.5 20150623 (Red Hat 4.8.5-36)] on linux2
Type "help", "copyright", "credits" or "license" for more information.

输入Python命令，查看可以得知是Python2.7.5版本

which python

可以查看位置，一般是位于/usr/bin/python目录下。

下面介绍安装Python3的方法

首先安装依赖包

yum -y groupinstall "Development tools"
yum -y install zlib-devel bzip2-devel openssl-devel ncurses-devel sqlite-devel readline-devel tk-devel gdbm-devel db4-devel libpcap-devel xz-devel

然后根据自己需求下载不同版本的Python3，我下载的是Python3.6.2

mkdir /usr/local/python3 创建一个文件夹
cd /usr/local/python3  进入文件夹

wgt https://www.python.org/ftp/python/3.6.2/Python-3.6.2.tar.xz

建立一个空文件夹

然后解压压缩包，进入该目录，安装Python3

tar -xvJf  Python-3.6.2.tar.xz
cd Python-3.6.2
./configure --prefix=/usr/local/python3
make && make install

最后创建软链接

ln -s /usr/local/python3/bin/python3 /usr/bin/python3
ln -s /usr/local/python3/bin/pip3 /usr/bin/pip3

在命令行中输入python3测试

上面我们已经把python3跟pip3安装好了，接下来，我们进行Python3下的Scrapy框架安装

3 安装Scrapy爬虫框架

（1）安装Scrapy

[root@hadron ~]# pip3 install scrapy
Collecting scrapy
  Downloading Scrapy-1.5.0-py2.py3-none-any.whl (251kB)
    100% |████████████████████████████████| 256kB 1.1MB/s 
Requirement already satisfied: lxml in /usr/local/python3/lib/python3.5/site-packages (from scrapy)
Collecting PyDispatcher>=2.0.5 (from scrapy)
  Downloading PyDispatcher-2.0.5.tar.gz
....
....
Collecting pycparser (from cffi>=1.7; platform_python_implementation != "PyPy"->cryptography>=2.1.4->pyOpenSSL->scrapy)
  Downloading pycparser-2.18.tar.gz (245kB)
    100% |████████████████████████████████| 256kB 339kB/s 
Installing collected packages: PyDispatcher, zope.interface, constantly, incremental, six, attrs, Automat, hyperlink, Twisted, cssselect, w3lib, parsel, asn1crypto, pycparser, cffi, cryptography, pyOpenSSL, pyasn1, pyasn1-modules, service-identity, queuelib, scrapy
  Running setup.py install for PyDispatcher ... done
  Running setup.py install for Twisted ... done
  Running setup.py install for pycparser ... done
Successfully installed Automat-0.6.0 PyDispatcher-2.0.5 Twisted-17.9.0 asn1crypto-0.24.0 attrs-17.4.0 cffi-1.11.4 constantly-15.1.0 cryptography-2.1.4 cssselect-1.0.3 hyperlink-18.0.0 incremental-17.5.0 parsel-1.4.0 pyOpenSSL-17.5.0 pyasn1-0.4.2 pyasn1-modules-0.2.1 pycparser-2.18 queuelib-1.4.2 scrapy-1.5.0 service-identity-17.0.0 six-1.11.0 w3lib-1.19.0 zope.interface-4.4.3
[root@hadron ~]#

在这里进行安装的时候，我们可能会出现一串的报红，一串的报红。

 

很蛋疼的报红信息

出现报红不要紧，我们多试几次pip3 install scrapy 就行了

（2）网络好的话，试下不超过5次，应该就会出现下面安装成功的界面

 

成功安装Scrapy的界面

（3）上面的图也是验证Scrapy框架安装成功的界面，因为我们进行了import scrapy没有进行报错。

（4）创建Scrapy软链接

root@hadron ~]# ln -s /usr/local/python3/bin/scrapy  /usr/bin/scrapy

（5）验证Scrapy软链接

[root@hadron ~]#  scrapy -v
Scrapy 1.5.0 - no active project

上面就是整个Python3下Scrapy框架的安装步骤过程，基本上没有bug。

  

 转载 https://www.jianshu.com/p/aca9967a7136