centos 7 安装python3 & pip3

1、安装python3

https://www.cnblogs.com/Trees/p/7497482.html

2、解决：python ModuleNotFoundError: No module named '_ctypes'

3.7版本需要一个新的包libffi-devel，安装此包之后再次进行编译安装即可。
yum install libffi-devel -y

3、安装pip3

1.首先安装setuptools
wget --no-check-certificate https://pypi.python.org/packages/source/s/setuptools/setuptools-19.6.tar.gz#md5=c607dd118eae682c44ed146367a17e26

tar -zxvf setuptools-19.6.tar.gz
cd setuptools-19.6.tar.gz
python3 setup.py build
python3 setup.py install

2.然后直接安装pip就搞定了。。
wget --no-check-certificate https://pypi.python.org/packages/source/p/pip/pip-8.0.2.tar.gz#md5=3a73c4188f8dbad6a1e6f6d44d117eeb

tar -zxvf pip-8.0.2.tar.gz
cd pip-8.0.2
python3 setup.py build
python3 setup.py install

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