安裝python3centos7安裝python3的步驟

需要做pip3和python3的軟連線，這樣python3和pip3就都能用了

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

直接執行

pip3 install scrapy

可能會報下面的錯誤

 Could not find a version that satisfies the requirement Twisted>=13.1.0 (from scrapy) (from versions: ) No matching distribution found for Twisted>=13.1.0 (from scrapy)
 

需要安裝Twisted>=13.1.0

# virtualenv --python=python3.6 ENV
# source ENV/bin/activate
wget https://twistedmatrix.com/Releases/Twisted/17.1/Twisted-17.1.0.tar.bz2
tar -jxvf Twisted-17.1.0.tar.bz2
cd Twisted-17.1.0
python3 setup.py install
cd ..

按步驟或者一次性解除安裝腳本里

然後再繼續執行

pip3 install scrapy