CentOS7 升級 python3 過程及注意

CentOS7 升級 python3 過程及注意

檢查當前的版本
[root@node1 ~]# python -V
Python 2.7.5
建立安裝目錄（自定義）
[root@node1 Python-3.7.1]# mkdir /usr/local/python3

從官網下載python3的壓縮包，解壓（以3.7.1版本爲例）
# wget https://www.python.org/ftp/python/3.7.1/Python-3.7.1.tgz
# tar zxf Python-3.7.1.tgz 

cd 進入解壓目錄，而後
# cd Python-3.7.1
# ./configure --prefix=/usr/local/python3/
# make && make install

cd 進入/usr/bin
其中有python、python二、python2.7三個文件依次指向後者。
備份當前默認版本python，若是有須要還可還原：
# sudo mv python python.bak

建立python3.7的新連接（也可創建python3命令以區分，同mac），這樣默認的python版本就替換爲python3.7了
# ln -s /usr/local/python3/bin/python3.7 /usr/bin/python

檢查當前默認python版本
# python -v

因爲yum使用python2，替換爲python3後沒法正常工做，
所以修改yum配置文件:
# sudo vi /usr/bin/yum
將第一行指定的python版本改成python2.7:
*#!/usr/bin/python 改成 #!/usr/bin/python2.7

修改urlgrabber配置文件（網上不少教程都漏了這一步）
# sudo vi /usr/libexec/urlgrabber-ext-down
同yum，把頭部的python改爲python2.7

連接：https://www.jianshu.com/p/74227d7ae6a6

問題

Python安裝完畢後，提示找不到ssl模塊：

(<http://blog.csdn.net/qq_25560423/article/details/62055497>;)

例如這樣： 

pip is configured with locations that require TLS/SSL, however the ssl module in Python is not available. 

Collecting xxx 

Could not fetch URL <https://pypi.python.org/simple/xxxx/>: There was a problem confirming the ssl certificate: Can’t connect to HTTPS URL because the SSL module is not available. - skipping 

Could not find a version that satisfies the requirement xxx (from versions: ) 

No matching distribution found for xxx

[root@localhost ~]# python2.7.5

Python 2.7.5 (default, Jun 3 2013, 11:08:43)

[GCC 4.1.2 20080704 (Red Hat 4.1.2-54)] on linux2

Type 「help」, 「copyright」, 「credits」 or 「license」 for more information.

import ssl

Traceback (most recent call last):

File 「」, line 1, in

File 「/usr/local/python27/lib/python2.7/ssl.py」, line 60, in

import _ssl # if we can’t import it, let the error propagate

ImportError: No module named _ssl

---

1. 查看openssl安裝包，發現缺乏openssl-devel包

   [root@localhost ~]# rpm -aq|grep openssl

   openssl-0.9.8e-20.el5

   openssl-0.9.8e-20.el5

   [root@localhost ~]#

2. yum安裝openssl-devel

   [root@localhost ~]# yum install openssl-devel -y

   查看安裝結果

   [root@localhost ~]# rpm -aq|grep openssl

   openssl-0.9.8e-26.el5_9.1

   openssl-0.9.8e-26.el5_9.1

   openssl-devel-0.9.8e-26.el5_9.1

   openssl-devel-0.9.8e-26.el5_9.1

3. 從新編譯python

   修改Setup文件

   vi /usr/software/Python-2.7.5/Modules/Setup

   修改爲下面：

Socket module helper for socket(2)

_socket socketmodule.c timemodule.c

Socket module helper for SSL support; you must comment out the other

socket line above, and possibly edit the SSL variable:

SSL=/usr/local/ssl

_ssl _ssl.c \

-DUSE_SSL -I$(SSL)/include -I$(SSL)/include/openssl \

-L$(SSL)/lib -lssl -lcrypto

1. 從新編譯

   make

   make install

2. 測試，已可正常使用。

   [root@localhost ~]# python2.7.5

   Python 2.7.5 (default, Jun 3 2013, 14:56:13)

   [GCC 4.1.2 20080704 (Red Hat 4.1.2-54)] on linux2

   Type 「help」, 「copyright」, 「credits」 or 「license」 for more information.

   import ssl

從新用pip安裝