Linux/Mac下python3配置

1. 查看原python版本

linux系统都会默认安装python2.7，使用命令：python --version即可查看。因为有些系统功能依赖python2，不建议删除。

2. 安装依赖包

首先安装依赖包，centos里面是-devel，如果在ubuntu下安装则要改成-dev，依赖包缺一不可，一步一步复制到终端执行就可以！

sudo yum -y groupinstall "Development tools"
sudo 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 libffi-devel

3. 下载安装

## 下载
wget https://www.python.org/ftp/python/3.7.3/Python-3.7.3.tar.xz

## 解压
tar -xvJf  Python-3.7.3.tar.xz

## 编译安装
cd Python-3.7.3
./configure --prefix=/usr/local/bin/python3
sudo make & make install

## 创建软连接
ln -s /usr/local/bin/python3/bin/python3 /usr/bin/python3
ln -s /usr/local/bin/python3/bin/pip3 /usr/bin/pip3

最后输入命令python3 --version检查一下是否安装成功

4. 默认python3配置

alias python2=/usr/bin/python
alias python3=/usr/local/python3/bin/python3
alias python=/usr/local/python3/bin/python3