Centos/Linux 下升级python2.7至3.5.0
(一) 安装Python3.5
(1)在安装python之前，因为linux系统下默认没有安装wget，gcc，首先安装wget，gcc：
1[root@node6 python_scripts]#yuminstallwget2[root@node6 python_scripts]#yuminstallgcc
(2)安装依赖：
!!!在编译之前需要安装一些必须的依赖，否则当报错的时候还得重新编译
yuminstallopenssl-devel -yyuminstallzlib-devel -y
(3)利用wget下载python3.5.0的安装文件并解压缩：
1[root@node6 python_scripts]#wgethttps://www.python.org/ftp/python/3.5.0/Python-3.5.0.tgz2[root@node6 python_scripts]#ls3Python-3.5.0.tgz4[root@node6 python_scripts]#tarxvf Python-3.5.0.tgz 5[root@node6 python_scripts]#ls6Python-3.5.0Python-3.5.0.tgz7[root@node6 Python-3.5.0]# cd Python-3.5.0
(4)编译：
1[root@node6 Python-3.5.0]# ./configure --prefix=/usr/local/python3.52[root@node6 Python-3.5.0]#make3[root@node6 Python-3.5.0]#makeinstall4[root@node6 Python-3.5.0]mv/usr/bin/python /usr/bin/python_bak5[root@node6 Python-3.5.0]ln-s /usr/local/python3.5/bin/python3.5/usr/bin/python
(5)此时执行phthon可以看到3.5已经运行：
1[root@node6 python_scripts]# python2Python3.5.0(default, Jul272016,09:34:49) 3[GCC4.8.520150623(Red Hat4.8.5-4)] on linux4Type"help","copyright","credits"or"license"formore information.5>>>
(6) 此时yum的运行会报错，如下操作可以恢复yum：
修改yum文件
1、cd /usr/bin2、ls-lyum*
会显示出“yum、yum-builddep、yum-config-manager、yum-debug-dump、yum-debug-restore、yumdownloader、yum-groups-manager”这7个yum开头的文件，这7个文件都是脚本文件，其第一行为：
#!/usr/bin/python
或
#!/usr/bin/python -tt
将“python”改为“python2.7”。
我们试着安装一个文件：
[root@vnode33 bin]# yum install tcpreplay
发现系统仍然报错：
Is this ok [y/d/N]: y
Downloading packages:
File "/usr/libexec/urlgrabber-ext-down", line28 except OSError, e:
^SyntaxError: invalid syntax
找到该文件[root@vnode33 libexec]# vi /usr/libexec/urlgrabber-ext-down
修改/usr/bin/python为/usr/bin/python2.7
可以安装成功了：
Is this ok [y/d/N]: y
Downloading packages:
tcpreplay-4.1.1-1.el7.x86_64.rpm |298kB00:00:00
Running transaction check
Running transaction test
Transaction test succeeded
Running transaction
Installing : tcpreplay-4.1.1-1.el7.x86_641/1
Verifying : tcpreplay-4.1.1-1.el7.x86_641/1
Installed:
tcpreplay.x86_64 0:4.1.1-1.el7
Complete!
或者也可以用以下的方法：
./configure --prefix=/opt/python #因为centos自带python，为了不影响原有系统，我这里是另外安装到新目录makeinstall 进行安装ln-s /opt/python/bin/python3.4/usr/bin/python3 #软连接到系统path所指向的一个目录中，使之成为系统命令ln-s /opt/python/bin/pip3.4/usr/bin/pip3ln-s /opt/python/bin/easy_install-3.4/usr/bin/easy_install3
(二)安装pip3：
(1)首先下载，安装依赖setuptools
wget--no-check-certificate https://pypi.python.org/packages/source/s/setuptools/setuptools-19.6.tar.gz#md5=c607dd118eae682c44ed146367a17e26tar-zxvf setuptools-19.6.tar.gz
cd setuptools-19.6.tar.gz
python3 setup.py build
python3 setup.py install
(2)安装pip3
1wget--no-check-certificate https://pypi.python.org/packages/source/p/pip/pip-8.0.2.tar.gz#md5=3a73c4188f8dbad6a1e6f6d44d117eeb2tar-zxvf pip-8.0.2.tar.gz3cd pip-8.0.24python3 setup.py build5python3 setup.pyinstall
安装完成之后我们再来查看python3.5的bin目录下都有什么东西：
1[root@vnode33 usr]# cd /usr/local/python3.5/bin/2[root@vnode33 bin]#ls32to3 easy_install idle3 pip pip3.5pydoc3.5python3.5python3.5m python3-config pyvenv-3.542to3-3.5easy_install-3.5idle3.5pip3 pydoc3 python3 python3.5-config python3.5m-config pyvenv
为pip3创建链接：
[root@vnode33 bin]#ln-s /usr/local/python3.5/bin/pip3 /usr/bin/pip
现在可以用了：
[root@vnode33 bin]# pip
Usage:
pip [options]
Commands:
install Install packages.
download Download packages.
uninstall Uninstall packages.
freeze Output installed packages in requirements format.
list List installed packages.
show Show information about installed packages.
search Search PyPI for packages.
wheel Build wheels from your requirements.
hash Compute hashes of package archives.
help Show help for commands.
...
(3)安装Twisted
Linux上设置https proxy并安装：
本机因从网络下载包时需要代理，故需要如下命令：
1export https_proxy=135.251.33.31:80802export http_proxy=135.251.33.31:80803export ftp_proxy=135.251.33.31:8080
然后下载安装：
1wgethttps://pypi.python.org/packages/source/T/Twisted/Twisted-15.2.1.tar.bz22tar-xjvf Twisted-15.2.1.tar.bz23cd Twisted-15.2.1/4python setup.pyinstall
检查是否安装成功：
1[root@vnode33 ~]# python2Python3.5.0(default, Feb162017,12:30:39) 3[GCC4.8.520150623(Red Hat4.8.5-4)] on linux4Type"help","copyright","credits"or"license"formore information.5>>> import twisted6>>>
(4)安装Scrapy
pipinstallScrapy
这个时候安装成功了，但是运行scrapy时报错
再重新安装下Twisted最新的版本：
1wgethttps://twistedmatrix.com/Releases/Twisted/17.1/Twisted-17.1.0.tar.bz22tar-xjvf Twisted-17.1.0.tar.bz23cd Twisted-17.1.0/4python setup.pyinstall
再运行scrapy发现已经好了：
[root@vnode33 bin]# ./scrapy
Scrapy 1.3.2- no active project
Usage:
scrapy [options] [args]
Available commands:
bench Run quick benchmark test
commands
fetch Fetch a URL using the Scrapy downloader
genspider Generate new spider using pre-defined templates
runspider Run a self-contained spider (without creating a project)
settings Get settings values
shell Interactive scraping console
startproject Create new project
version Print Scrapy version
view Open URL in browser, as seen by Scrapy
[ more ] More commands available when run from project directory
Use "scrapy -h"to seemoreinfoabout a command
还需要做一个软链接让scrapy命令全局可用：
ln-s /usr/local/python3.5/bin/scrapy /usr/bin/scrapy
试试在Python中导入scrapy:
1Python3.5.0(default, Feb162017,12:30:39) 2[GCC4.8.520150623(Red Hat4.8.5-4)] on linux3Type"help","copyright","credits"or"license"formore information.4>>> from scrapy.spider import BaseSpider5__main__:1: ScrapyDeprecationWarning: Module `scrapy.spider` is deprecated, use `scrapy.spiders` instead6>>> from scrapy.spiders import BaseSpider
安装scrapy过程中有三步不确定是否需要，附录如下：
1，libxml2
wgetftp://xmlsoft.org/libxml2/libxml2-git-snapshot.tar.gztar-zxvf libxml2-git-snapshot.tar.gz
cd libxml2-2.9.2/./configuremakemakeinstall
2，libxlst
wgethttp://xmlsoft.org/sources/libxslt-1.1.28.tar.gztar-zxvf libxslt-1.1.28.tar.gz
cd libxslt-1.1.28/./configuremakemakeinstall
3，cryptography
wgetftp://sourceware.org/pub/libffi/libffi-3.2.1.tar.gztar-zxvf libffi-3.2.1.tar.gz
cd libffi-3.2.1./configuremakemakeinstall
export PKG_CONFIG_PATH=/usr/local/lib/pkgconfig:$PKG_CONFIG_PATH
wgetftp://sourceware.org/pub/libffi/libffi-3.2.1.tar.gztar-zxvf libffi-3.2.1.tar.gz
cd libffi-3.2.1./configuremakemakeinstall
Windows7下安装scrapy:
先下载python-3.5.2.exe 双击文件安装成功：
然后直接安装scrapy，找到pip文件的目录：
cd C:\Users\xxx\AppData\Local\Programs\Python\Python35-32\Scripts
pipinstallscrapy
安装成功后测试下：
C:\Users\xxx>python
Python 3.5.2(v3.5.2:4def2a2901a5, Jun252016,22:01:18) [MSC v.190032 bit (In
tel)] on win32
Type "help","copyright","credits"or"license"formore information.>>> from scrapy.spiders import BaseSpider>>> exit()
(三)IDLE支持方向键：
(1)安装readline
pipinstallreadline
但是有如下报错：
gcc: error: readline/libreadline.a: No suchfileor directory
解决方法：
yuminstallreadline-develyuminstallpatch
再重新configure、make、makeinstallpython3.5
出处：https://www.cnblogs.com/z-joshua/p/5710698.html
