安裝Python3.6
1. # Centos7默認的 repo有限， 安裝epel
rpm -ivh http://dl.fedoraproject.org/pub/epel/7/x86_64/Packages/e/epel-release-7-11.noarch.rpm
2. 安裝python3.6可能使用的依賴
# yum install openssl-devel bzip2-devel expat-devel gdbm-devel readline-devel sqlite-devel zlib-devel -y
3. 下載python3.6編譯安裝
到python官網下載https://www.python.org
下載最新版源碼，使用make altinstall，如果使用make install，在系統中將會有兩個不同版本的Python在/usr/bin/目錄中。這將會導致很多問題，而且不好處理。
# wget https://www.python.org/ftp/python/3.6.4/Python-3.6.4.tgz
# tar -xzvf Python-3.6.4.tgz -C ?/tmp
# cd?/tmp/Python-3.6.4/
把Python3.6安裝到/usr/local 目錄
# ./configure --prefix=/usr/local/
note: 如遇到 "error: no acceptable C compiler found in $PATH"
[root@localhost Python-3.6.4]# yum install gcc -y
# make
# make altinstall
Note: 如遇錯誤，請安裝依賴包。
zipimport.ZipImportError: can't decompress data; zlib not available
make: *** [altinstall] Error 1
[root@localhost Python-3.6.4]# yum install bzip2-devel -y
[root@localhost Python-3.6.4]# yum install zlib-devel -y
[root@localhost Python-3.6.4]# yum install zlib2 -y
[root@localhost Python-3.6.4]# yum install zlib -y
----------------
python3 安裝成功，信息如下：
。。。。
Collecting setuptools
Collecting pip
Installing collected packages: setuptools, pip
Successfully installed pip-9.0.1 setuptools-28.8.0
------------------------
python3.6程序的執行文件：/usr/local/bin/python3.6
python3.6應用程序目錄：/usr/local/lib/python3.6
pip3的執行文件：/usr/local/bin/pip3.6
pyenv3的執行文件：/usr/local/bin/pyenv-3.6
[root@localhost Python-3.6.4]# whereis pip
pip: /usr/local/bin/pip3.6
[root@localhost Python-3.6.4]#
4. 更改/usr/bin/python鏈接 （默認是Python2.7）
[root@localhost Python-3.6.4]# ls -l /usr/bin/python*
lrwxrwxrwx. 1 root root? ? 7 Jan 20? 2018 /usr/bin/python -> python2
lrwxrwxrwx. 1 root root? ? 9 Jan 20? 2018 /usr/bin/python2 -> python2.7
-rwxr-xr-x. 1 root root 7136 Aug? 3 20:40 /usr/bin/python2.7
# cd /usr/bin
# mv ?python python.backup
# ln -s /usr/local/bin/python3.6 /usr/bin/python
# ln -s /usr/local/bin/python3.6 /usr/bin/python3
至此，python3已經安裝完畢，測試一下：
[root@localhost bin]# whereis python
python: /usr/bin/python /usr/bin/python2.7 /usr/bin/python.backup /usr/lib/python2.7 /usr/lib64/python2.7 /etc/python /usr/local/bin/python3.6m /usr/local/bin/python3.6 /usr/local/bin/python3.6m-config /usr/local/lib/python3.6 /usr/include/python2.7 /usr/share/man/man1/python.1.gz
[root@localhost bin]# python
Python 3.6.4 (default, Jan 20 2018, 03:11:08)
[GCC 4.8.5 20150623 (Red Hat 4.8.5-16)] on linux
Type "help", "copyright", "credits" or "license" for more information.
安裝virtualenv:
Note: 默認pip是使用Python官方的源，但是由于國外官方源經常被墻，導致不可用，我們可以使用國內的python鏡像源，從而解決Python安裝不上庫的煩惱。
網上有很多可用的源，例如：
豆瓣：http://pypi.douban.com/simple/
清華：https://pypi.tuna.tsinghua.edu.cn/simple
注意后面要有/simple目錄！！！?
[root@localhost ~]# pip install -i http://pypi.douban.com/simple/ virtualenv
--trusted-host pypi.douban.com
Collecting virtualenv
? Downloading http://pypi.doubanio.com/packages/b6/30/96a02b2287098b23b875bc8c2f58071c35d2efe84f747b64d523721dc2b5/virtualenv-16.0.0-py2.py3-none-any.whl (1.9MB)
??? | 99% |鈻堚枅鈻堚枅鈻堚枅鈻堚枅鈻堚枅鈻堚枅鈻堚枅鈻堚枅鈻堚枅鈻堚枅鈻堚枅鈻堚枅鈻堚枅鈻堚枅鈻堚枅鈻堚枆| 1.9MB 8.3MB/s eta? ? 100% |鈻堚枅鈻堚枅鈻堚枅鈻堚枅鈻堚枅鈻堚枅鈻堚枅鈻堚枅鈻堚枅鈻堚枅鈻堚枅鈻堚枅鈻堚枅鈻堚枅鈻堚枅鈻堚枅| 1.9MB 7.7MB/s
Installing collected packages: virtualenv
Successfully installed virtualenv-16.0.0
You are using pip version 9.0.1, however version 18.0 is available.
You should consider upgrading via the 'pip install --upgrade pip' command.
[root@localhost ~]# virtualenv myenv1
Using base prefix '/usr/local'
New python executable in /root/myenv1/bin/python3.6
Also creating executable in /root/myenv1/bin/python
Installing setuptools, pip, wheel...done.
[root@localhost ~]# pwd
/root
[root@localhost ~]# source myenv1/bin/activate
(myenv1) [root@localhost ~]#
Note: 如果在公司訪問，使用代理的話：
[root@localhost ~]# export http_proxy="http://1**.2**.33.**:80"
[root@localhost download]# pip install -i http://pypi.douban.com/simple/ virtualenv --trusted-host pypi.douban.com
Collecting virtualenv
? Downloading http://pypi.doubanio.com/packages/b6/30/96a02b2287098b23b875bc8c2f58071c35d2efe84f747b64d523721dc2b5/virtualenv-16.0.0-py2.py3-none-any.whl (1.9MB)
? ? 100% |鈻堚枅鈻堚枅鈻堚枅鈻堚枅鈻堚枅鈻堚枅鈻堚枅鈻堚枅鈻堚枅鈻堚枅鈻堚枅鈻堚枅鈻堚枅鈻堚枅鈻堚枅鈻堚枅| 1.9MB 56.1MB/s
Installing collected packages: virtualenv
Successfully installed virtualenv-16.0.0
Important:
1.修改腳本
Centos7下很多腳本是基于python2.7的，安裝完python3以后，很多腳本無法正常使用（比如yum）， 需要在腳本文件開頭更改：
#!/usr/bin/python?? ===》 #!/usr/bin/python2.7
2.pip3.6 install django
會報錯！！
例如這樣：
pip is configured with locations that require TLS/SSL, however the ssl module in Python is not available.
Collecting xxx
Could not fetch URLhttps://pypi.python.org/simple/xxxx/: There was a problem confirming the ssl certificate: Can’t connect to HTTPS URL because the SSL module is not available. - skipping
Could not find a version that satisfies the requirement xxx (from versions: )
No matching distribution found for xxx
===》solution:
yum install openssl-devel
重新 make & make install?
===> 這表明 要先裝python的依賴包，先裝python的依賴包，先裝python的依賴包，重要事情說3遍！ 然后 make & make install 等等
http://blog.csdn.net/a249900679/article/details/51527200? Centos7服務器搭建django項目
