.install 的时候需要gcc
make install 的时候需要zlib-devel

编译安装

如果缺少依赖包，编辑的时候就会有问题。到时候就查看错误信息，到网上搜一下，看看是缺少了哪个依赖包：

[root@Python36 download]# cd Python-3.6.6
[root@Python36 Python-3.6.6]# ./configure prefix=/usr/local/python3

指定安装目录是：/usr/local/python3。
如果不指定安装目录的话，安装后可执行文件默认放在/usr/local/bin（默认放这里的可执行文件后面就不用另外再创建软链接了），库文件默认放在/usr/local/lib，配置文件默认放在/usr/local/etc，其它的资源文件放在/usr/local/share，比较凌乱。似乎也不是太乱的样子，不过网上的文章都推荐在默认位置下再建一级目录，全部放一起，就是这里的做法。
我们指定安装目录，以后卸载的话直接删除目录就可以干净卸载了。
然后make：

[root@Python36 Python-3.6.6]# make

这里遇到报错了：

gcc -pthread   -Xlinker -export-dynamic -o Programs/_testembed Programs/_testembed.o libpython3.6m.a -lpthread -ldl  -lutil   -lm  
# Substitution happens here, as the completely-expanded BINDIR
# is not available in configure
sed -e "s,@EXENAME@,/usr/local/python3/bin/python3.6m," < ./Misc/python-config.in >python-config.py
# Replace makefile compat. variable references with shell script compat. ones;  -> 
LC_ALL=C sed -e 's,\$(\([A-Za-z0-9_]*\)),\$\{\1\},g' < Misc/python-config.sh >python-config
# On Darwin, always use the python version of the script, the shell
# version doesn't use the compiler customizations that are provided
# in python (_osx_support.py).
if test `uname -s` = Darwin; then \
        cp python-config.py python-config; \
fi
[root@Python36 Python-3.6.6]#

直接根据提示运行上面给的命令，然后再make：

[root@Python36 Python-3.6.6]# sed -e "s,@EXENAME@,/usr/local/python3/bin/python3.6m," < ./Misc/python-config.in >python-config.py
[root@Python36 Python-3.6.6]# make
 CC='gcc -pthread' LDSHARED='gcc -pthread -shared  ' OPT='-DNDEBUG -g -fwrapv -O3 -Wall'        _TCLTK_INCLUDES='' _TCLTK_LIBS=''   ./python -E ./setup.py  build
running build
running build_ext
INFO: Can't locate Tcl/Tk libs and/or headers
warning: building with the bundled copy of libffi is deprecated on this platform.  It will not be distributed with Python 3.7

Python build finished successfully!
The necessary bits to build these optional modules were not found:
_bz2                  _curses               _curses_panel      
_dbm                  _gdbm                 _lzma              
_sqlite3              _ssl                  _tkinter           
readline              zlib                                     
To find the necessary bits, look in setup.py in detect_modules() for the module's name.

The following modules found by detect_modules() in setup.py, have been
built by the Makefile instead, as configured by the Setup files:
atexit                pwd                   time               
running build_scripts
copying and adjusting /root/download/Python-3.6.6/Tools/scripts/pydoc3 -> build/scripts-3.6
copying and adjusting /root/download/Python-3.6.6/Tools/scripts/idle3 -> build/scripts-3.6
copying and adjusting /root/download/Python-3.6.6/Tools/scripts/2to3 -> build/scripts-3.6
copying and adjusting /root/download/Python-3.6.6/Tools/scripts/pyvenv -> build/scripts-3.6
changing mode of build/scripts-3.6/pydoc3 from 644 to 755
changing mode of build/scripts-3.6/idle3 from 644 to 755
changing mode of build/scripts-3.6/2to3 from 644 to 755
changing mode of build/scripts-3.6/pyvenv from 644 to 755
renaming build/scripts-3.6/pydoc3 to build/scripts-3.6/pydoc3.6
renaming build/scripts-3.6/idle3 to build/scripts-3.6/idle3.6
renaming build/scripts-3.6/2to3 to build/scripts-3.6/2to3-3.6
renaming build/scripts-3.6/pyvenv to build/scripts-3.6/pyvenv-3.6
[root@Python36 Python-3.6.6]# 

make 成功后就是 make install ：

[root@Python36 Python-3.6.6]# make install

验证

直接先运行python3，再确认一下版本信息：

[root@Python36 ~]# cd /usr/local/python3/
[root@Python36 python3]# ./bin/python3
Python 3.6.6 (default, Sep 29 2018, 16:19:00) 
[GCC 4.8.5 20150623 (Red Hat 4.8.5-28)] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> exit()
[root@Python36 python3]# 

退出用 exit()

创建软链接

直接执行python3命令是找不到的，在python3的启动命令加一条软链接到系统目录：

[root@Python36 ~]# python3
-bash: python3: 未找到命令
[root@Python36 ~]# ln -s /usr/local/python3/bin/python3 /usr/bin/python3
[root@Python36 ~]# python3
Python 3.6.6 (default, Sep 29 2018, 16:19:00) 
[GCC 4.8.5 20150623 (Red Hat 4.8.5-28)] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> 

pip工具是安装各种python包的，也很常用，也加个软链接：

[root@Python36 ~]# ln -s /usr/local/python3/bin/pip3 /usr/bin/pip3
[root@Python36 ~]# pip3 --version
pip 10.0.1 from /usr/local/python3/lib/python3.6/site-packages/pip (python 3.6)

用python命令进入python3

还可以把默认的python的软链接也指向python3，就是把系统默认的用python命令启动python2给替换成启动python3。这样做的问题是，系统的yum使用要python2，因此替换为python3后，yum就无法正常工作了。
解决办法就是修改yum的配置文件 vi /usr/bin/yum ，然后找到开头的 #!/usr/bin/python 修改为 #!/usr/bin/python2.7 保存退出就好了。

yum安装

用yum的话，步骤简单多了，就是安装路径会分散在不同的目录里。

安装epel源

用下面的命令就可以安装好epel源。不过国外的源可能会比较慢，可以都换成国内的yum源。

[root@Python3 ~]# yum install epel-release

上面的步骤就不要做了。
先确认有没有wget命令：

[root@Python3 ~]# wget --version

如果没有就先装一下，之后下载yum源的文件要用：

[root@Python3 ~]# yum install wget

备份现在的yum源
备份是个好习惯，直接删也可以。然后发现wget没装，现在一个yum源也没有了，只能找其他办法了。

[root@Python3 ~]# cd /etc/yum.repos.d/
[root@Python3 yum.repos.d]# mkdir bak
[root@Python3 yum.repos.d]# mv *.repo bak
[root@Python3 yum.repos.d]# ls
bak

现在文件夹已经空了，去下载yum源的repo文件，我用的是阿里的源：

[root@Python3 yum.repos.d]# wget https://mirrors.aliyun.com/repo/Centos-7.repo
[root@Python3 yum.repos.d]# wget https://mirrors.aliyun.com/repo/epel-7.repo

然后可以makecache建立本地缓存：

[root@Python3 yum.repos.d]# yum makecache

安装python

这里装了python，另外还装了一个setuptools，之后的pip工具要通过setuptools来安装。

[root@Python3 yum.repos.d]# yum install python36 python36-setuptools

安装完之后要用python36命令来启动，这里可以添加一下python3命令的软连接：

[root@Python3 ~]# ln -s python36 /usr/bin/python3

安装pip

通过setuptools的easyinstall命令来安装pip：

[root@Python3 ~]# easy_install-3.6 pip

安装目录

python 和 setuptools 都在这个目录里：
/usr/lib/python3.6/site-packages/
而 pip 是在下面这个目录里，就是默认编译安装的目录：
/usr/local/lib/python3.6/site-packages
之后用pip安装的模块也都会在pip的这个目录里。