Linux CentOS7下安裝python3

在CentOS7下，默認安裝的就是python2.7，我如今來教你們如何安裝python3：

一、首先安裝python3.6可能使用的依賴

# yum -y install openssl-devel bzip2-devel expat-devel gdbm-devel readline-devel zlib-devel

二、下載python源碼包，地址爲https://www.python.org/downloads/source/，而後經過xftp上傳上去，或者直接使用wget命令，wget https://www.python.org/ftp/python/3.6.1/Python-3.6.1.tgz下載到本地

# tar -zxvf Python-3.6.1.tgz
# cd Python-3.6.1/

三、把python3.6安裝到/usr/local目錄下

# ./configure --prefix=/usr/local/  
# make  
# make altinstall  

四、更改/usr/bin/python連接

# 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  
# rm -rf /usr/bin/python2  
# ln -s /usr/bin/python2.7 /usr/bin/python2 

五、更改yum腳本的python依賴

# cd /usr/bin  
# ll yum* 

有如下文件：

-rwxr-xr-x 1 root root   802 Jan  2 17:53 yum  
-rwxr-xr-x 1 root root  9374 Jan  2 17:53 yum-builddep  
-rwxr-xr-x 1 root root  8091 Jan  2 17:53 yum-config-manager  
-rwxr-xr-x 1 root root  7610 Jan  2 17:53 yum-debug-dump  
-rwxr-xr-x 1 root root  7904 Jan  2 17:54 yum-debug-restore  
-rwxr-xr-x 1 root root 10906 Jan  2 17:54 yumdownloader  
-rwxr-xr-x 1 root root 11032 Jan  2 17:54 yum-groups-manager  

修改以上文件頭：#!/usr/bin/python 改成 #!/usr/bin/python2

能夠安裝一個tree測試一下

# yum -y install tree

若是出現如下報錯：File 「/usr/libexec/urlgrabber-ext-down」, line 28

vim /usr/libexec/urlgrabber-ext-down  

將/usr/bin/python改成/usr/bin/python2便可

這樣，yum安裝軟件的時候就不會報錯了，並且默認安裝的就是python3了，輸入python時，就會進入python3界面，若是想進入python2，那麼就輸入python2好了。