centOS 安裝Python3與python2並存

centOS 安裝Python3與python2並存

如果本機安裝了python2，儘量不要管他，使用python3運行python腳本就好，因爲可能有程序依賴目前的python2環境，

比如yum！！！！！

不要動現有的python2環境！

安裝python3.7

安裝依賴環境

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

下載Python3

wget https://www.python.org/ftp/python/3.7.0/Python-3.7.0.tar.xz

安裝python3

　　我個人習慣安裝在/usr/local/python3（具體安裝位置看個人喜好） 　　創建目錄：

mkdir -p /usr/local/python3

　　解壓下載好的Python-3.x.x.tgz.xz包

tar -zxvf Python-3.7.0.tgz

進入解壓後的目錄，編譯安裝。

cd Python-3.7.0
./configure --prefix=/usr/local/python3

1. make

cd /usr/local/python3/python3.7.0 && make

• 注意：這裏執行make && make install阿里雲會報錯，所以分開執行！

2. 報錯ModuleNotFoundError: No module named '_ctypes'

yum install libffi-devel -y

3. make install

make install

建立python3的軟鏈

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

並將/usr/local/python3/bin加入PATH

vim ~/.bash_profile
.bash_profile
# Get the aliases and functions
if [ -f ~/.bashrc ]; then
. ~/.bashrc
fi
# User specific environment and startup programs
PATH=$PATH:$HOME/bin:/usr/local/python3/bin
export PATH

按ESC，輸入:wq回車退出。

修改完記得執行行下面的命令，讓上一步的修改生效：

source ~/.bash_profile

檢查Python3及pip3是否正常可用：

python3 -V
# Python 3.7.0

pip3 -V
# pip 10.0.1 from /usr/local/python3/lib/python3.7/site-packages (python 3.7)

不行的話在創建一下pip3的軟鏈接

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

The end..