Upgrading Python on Linux

1. check the current Python Version

#python -V

or

#python --version

2. Download Python from FTP, https://www.python.org/ftp/python/

#wget https://www.python.org/ftp/python/3.7.0/Python-3.7.0a4.tgz 

3. unzip the tar.gz file

#tar -xvf Python-3.7.0a4.tgz

4. Install gcc++ compilar if needed.

#rpm -qa |grep gcc

#yum install make gcc gcc-c++

#rpm -qa |grep gcc

libgcc-4.8.5-16.el7_4.1.x86_64

gcc-4.8.5-16.el7_4.1.x86_64

gcc-c++-4.8.5-16.el7_4.1.x86_64

5. Confiure it

# cd /Python-3.7.0a4

#./configure

6. Compile it

#./make & make install

7. Now you can access Python 3.7

#python3

8. You also can change the symbolic link for python

#mv /usr/bin/python /usr/bin/python.bak

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

     You also have to change the followings as you have change the default path for python.

# vi /usr/bin/yum

#vi /usr/libexec/urlgrabber-ext-down

Change " #!/usr/bin/python" into "#!/usr/bin/python2"

Now you have upgraded python successfully. You can input "python" to access python 3 and input "python2" to access python 2.

You may encounter the following error when compile the file.

ERROR 1:

zipimport.ZipImportError: can't decompress data; zlib not available

make: *** [install] Error 1

Solutions: #yum install zlib*

ERROR 2:

ModuleNotFoundError: No module named '_ctypes'

make: *** [install] Error 1

# rpm -qa |grep libffi

libffi-3.0.13-18.el7.x86_64

[root@nbu773srv1 Python-3.7.0a4]# yum list |grep libffi

libffi.x86_64                               3.0.13-18.el7              @anaconda

libffi.i686                                 3.0.13-18.el7              base    

libffi-devel.i686                           3.0.13-18.el7              base    

libffi-devel.x86_64                         3.0.13-18.el7              base    

Solutions: #yum install libffi-devel.x86_64