Linux/Mac下python3配置

1. 查看原python版本

linux系統都會默認安裝python2.7，使用命令：python --version即可查看。因爲有些系統功能依賴python2，不建議刪除。

2. 安裝依賴包

首先安裝依賴包，centos裏面是-devel，如果在ubuntu下安裝則要改成-dev，依賴包缺一不可，一步一步複製到終端執行就可以！

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. 下載安裝

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

## 解壓
tar -xvJf  Python-3.7.3.tar.xz

## 編譯安裝
cd Python-3.7.3
./configure --prefix=/usr/local/bin/python3
sudo make & make install

## 創建軟連接
ln -s /usr/local/bin/python3/bin/python3 /usr/bin/python3
ln -s /usr/local/bin/python3/bin/pip3 /usr/bin/pip3

最後輸入命令python3 --version檢查一下是否安裝成功

4. 默認python3配置

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