前言
一、测试环境
二、具体步骤
- 1.查看已安装python版本
- 2.测试默认python
- 3.安装python3
- 3.1wget编译安装方式
- 3.1.1下载python3安装包
- 3.1.2.yum安装相关依赖包
- 3.1.3.进入安装目录安装python3
- 3.1.4.测试python3
- 3.2.yum直接安装方式
- 3.2.1.yum安装python3
- 3.2.2.测试python3
- 4.修改python链接路径
- 5.重点！！！修改yum脚本中对python的依赖
- 三、补充
- 6.（可有可无）.py在linux上的执行
- 6.1【直接】python版本 xxx.py
- 6.2【增加权限】chmod + X xxx.py 后 ./xxx.py
- 6.3【增加权限】chmod + X xxx.py 后 nohup python版本 -u xxxx.py > 日志.log 2>&1 &
- 7.（可有可无）暂停.py文件的后台运行【kill (端口号)】
- 四、常见问题
- 1.pip版本过低
- 1.1通过get-pip进行安装
- 1.2通过python进行升级
- 2.编码错误
- 2.1SyntaxError: Non-ASCII character ‘\xe5’ in file 1.py on line 2, but no encoding declared
- 2.2UnicodeEncodeError: 'gbk' codec can't encode character '\xbb' in position 227741: illegal multibyte sequence
- 总结
- 推荐几个国内源
- 一入深似海，白了少年头
- 啥都没有，就这样，摆烂~
- 如有错误欢迎指正，谢谢(●'◡'●)
前言
因为centos7自带python2.7版本，在大部分开发过程中，我们需要使用到python3进行测试，于是下载安装python3，近乎是一种刚需，至于是否设置默认python指向python3，则看个人习惯~提示：以下是正文内容基于个人实践~
一、测试环境
基于VMware的虚拟机，Centos7.4提示：实机效果跟虚拟机基本一致~
二、具体步骤
1.查看已安装python版本
[root@localhost ~]# python -V
-----------------
| python 2.7.5 |
-----------------2.测试默认python
[root@localhost ~]# python
-----------------------------------------------------------------------
Python 2.7.5 (default, Aug 4 2017, 00:39:18)
[GCC 4.8.5 20150623 (Red Hat 4.8.5-16)] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>>
>>>exit() #退出python
-----------------------------------------------------------------------3.安装python3
提示：python3安装方法很多种，wget、rpm、yum等等，本文通过常用的wget与yum进行示例~
3.1wget编译安装方式
3.1.1下载python3安装包
[root@localhost ~]# yum install -y wget #wget用来从指定的URL中下载文件
[root@localhost ~]# wget https://www.python.org/ftp/python/3.6.1/Python-3.6.1.tgz
#本文下载的是官网的3.6.1，截止发布URL仍是正确的，如需其他版本替换成相对应版本极了
-----------------------------------------------------------------------
--2022-04-30 09:03:22-- https://www.python.org/ftp/python/3.6.1/Python-3.6.1.tgz
Resolving www.python.org (www.python.org)... 199.232.44.223, 2a04:4e42:48::223
Connecting to www.python.org (www.python.org)|199.232.44.223|:443... connected.
HTTP request sent, awaiting response... 200 OK
Length: 22540566 (21M) [application/octet-stream]
Saving to: ‘Python-3.6.1.tgz’
4% [=> ]
-----------------------------------------------------------------------提示：wget下载这个得看脸，要是有其他稳定来源咱也...
3.1.2.yum安装相关依赖包
[root@localhost ~]# yum -y install openssl-devel bzip2-devel expat-devel gdbm-devel readline-devel zlib-devel gcc
-----------------------------------------------------------------------
Installed:
bzip2-devel.x86_64 0:1.0.6-13.el7 expat-devel.x86_64 0:2.1.0-14.el7_9
gcc.x86_64 0:4.8.5-44.el7 gdbm-devel.x86_64 0:1.10-8.el7
openssl-devel.x86_64 1:1.0.2k-25.el7_9 readline-devel.x86_64 0:6.2-11.el7
zlib-devel.x86_64 0:1.2.7-19.el7_9
Dependency Installed:
cpp.x86_64 0:4.8.5-44.el7 glibc-devel.x86_64 0:2.17-325.el7_9
glibc-headers.x86_64 0:2.17-325.el7_9 kernel-headers.x86_64 0:3.10.0-1160.62.1.el7
keyutils-libs-devel.x86_64 0:1.5.8-3.el7 krb5-devel.x86_64 0:1.15.1-51.el7_9
libcom_err-devel.x86_64 0:1.42.9-19.el7 libkadm5.x86_64 0:1.15.1-51.el7_9
libmpc.x86_64 0:1.0.1-3.el7 libselinux-devel.x86_64 0:2.5-15.el7
libsepol-devel.x86_64 0:2.5-10.el7 libverto-devel.x86_64 0:0.2.5-4.el7
mpfr.x86_64 0:3.1.1-4.el7 ncurses-devel.x86_64 0:5.9-14.20130511.el7_4
pcre-devel.x86_64 0:8.32-17.el7
Dependency Updated:
e2fsprogs.x86_64 0:1.42.9-19.el7 e2fsprogs-libs.x86_64 0:1.42.9-19.el7
expat.x86_64 0:2.1.0-14.el7_9 glibc.x86_64 0:2.17-325.el7_9
glibc-common.x86_64 0:2.17-325.el7_9 krb5-libs.x86_64 0:1.15.1-51.el7_9
libcom_err.x86_64 0:1.42.9-19.el7 libgcc.x86_64 0:4.8.5-44.el7
libgomp.x86_64 0:4.8.5-44.el7 libselinux.x86_64 0:2.5-15.el7
libselinux-python.x86_64 0:2.5-15.el7 libselinux-utils.x86_64 0:2.5-15.el7
libsepol.x86_64 0:2.5-10.el7 libss.x86_64 0:1.42.9-19.el7
ncurses.x86_64 0:5.9-14.20130511.el7_4 ncurses-base.noarch 0:5.9-14.20130511.el7_4
ncurses-libs.x86_64 0:5.9-14.20130511.el7_4 openssl.x86_64 1:1.0.2k-25.el7_9
openssl-libs.x86_64 1:1.0.2k-25.el7_9 readline.x86_64 0:6.2-11.el7
zlib.x86_64 0:1.2.7-19.el7_9
Complete!
-----------------------------------------------------------------------3.1.3.进入安装目录安装python3
[root@localhost ~]# tar -zxvf Python-3.6.1.tgz
[root@localhost ~]# cd Python-3.6.1/
[root@localhost ~]# ./configure --prefix=/usr/local/
----------------------------------------------
creating Modules/Setup
creating Modules/Setup.local
creating Makefile
---------------------------------------------
[root@localhost ~]# make
[root@localhost ~]# make altinstall3.1.4.测试python3
[root@localhost ~]# python3.6
------------------------------------------------------------------------
Python 3.6.1 (default, Apr 30 2022, 09:19:51)
[GCC 4.8.5 20150623 (Red Hat 4.8.5-44)] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> exit()
------------------------------------------------------------------------3.2.yum直接安装方式
3.2.1.yum安装python3
提示：yum安装是基于你centos的yum源，可以通过添加诸如阿里源、163源等进行拓充~
[root@localhost ~]# yum list python3
---------------------------------------------------------------------------
Loaded plugins: fastestmirror
Loading mirror speeds from cached hostfile
* base: mirrors.ustc.edu.cn
* extras: mirrors.aliyun.com
* updates: mirrors.aliyun.com
Available Packages
python3.i686 3.6.8-18.el7 updates
python3.x86_64 3.6.8-18.el7 updates
---------------------------------------------------------------------------
[root@localhost ~]# yum install -y python3
---------------------------------------------------------------------------
Installed:
python3.x86_64 0:3.6.8-18.el7
Dependency Installed:
libtirpc.x86_64 0:0.2.4-0.16.el7 python3-libs.x86_64 0:3.6.8-18.el7
python3-pip.noarch 0:9.0.3-8.el7 python3-setuptools.noarch 0:39.2.0-10.el7
Complete!
---------------------------------------------------------------------------3.2.2.测试python3
[root@localhost ~]# python3 -V
---------------------------------
Python 3.6.8
---------------------------------4.修改python链接路径
通过上文下载，我们进行python测试，发现…
[root@localhost ~]# python
-----------------------------------------------------------------------
Python 2.7.5 (default, Aug 4 2017, 00:39:18)
[GCC 4.8.5 20150623 (Red Hat 4.8.5-16)] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>>
>>>exit() #退出python
-----------------------------------------------------------------------其实这是我们只是下载了python3，但是并没有指定默认使用python3提示：下文修改python默认因人而异，习惯问题！！！ 因为把默认python路径改成指向python3而不是python2，是个人习惯问题（其实就是懒！！！）
所以如果你大部分时候用的python2，就没有必要修改了，以后需要python3再使用python3指向就好~
[root@localhost ~]# cd /usr/bin
[root@localhost bin]# mv python python.backup #移除原来的python指向
[root@localhost bin]# ln -s /usr/local/bin/python3.6 /usr/bin/python #将python指向成python3.6
[root@localhost bin]# python #测试python的指向
-----------------------------------------------------------------------
Python 3.6.1 (default, Apr 30 2022, 09:19:51)
[GCC 4.8.5 20150623 (Red Hat 4.8.5-44)] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>>
>>>exit()
-----------------------------------------------------------------------
[root@localhost bin]# python2
-----------------------------------------------------------------------
Python 2.7.5 (default, Aug 4 2017, 00:39:18)
[GCC 4.8.5 20150623 (Red Hat 4.8.5-16)] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>>
>>> exit()
-----------------------------------------------------------------------
[root@localhost bin]# python3
-----------------------------------------------------------------------
Python 3.6.8 (default, Nov 16 2020, 16:55:22)
[GCC 4.8.5 20150623 (Red Hat 4.8.5-44)] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>>
>>> exit()
-----------------------------------------------------------------------提示：为啥俺的python3是3.6.8，因为俺装了三个版本的python~
[root@localhost bin]# python2 -V
--------------------------------------
|Python 2.7.5 |
--------------------------------------
[root@localhost bin]# python3 -V
--------------------------------------
|Python 3.6.8 |
--------------------------------------
[root@localhost bin]# python3.6 -V
--------------------------------------
|Python 3.6.1 |
--------------------------------------根据实际需求修改具体指向即可~
5.重点！！！修改yum脚本中对python的依赖
yum很多依赖的是python2，我猜这也是为啥centos7自带python2的原因
所以！！！重点！！！
[root@localhost bin]# cd /usr/bin
[root@localhost bin]# ll yum*
-------------------------------------------------
-rwxr-xr-x. 1 root root 801 Aug 5 2017 yum
#相关文件都需要更改，这里不只一个！！！（因为是新装未使用且为虚拟机，这里只有一个）
--------------------------------------------------
[root@localhost bin]# vi yum
[root@localhost bin]# cat yum
-----------------------------
#!/usr/bin/python
......
-----------------------------
#将相关文件头中的python指向修改成python2【因为你现在python默认指向python3！！！】
-----------------------------
#!/usr/bin/python2
......
-----------------------------
[root@localhost bin]# vim /usr/libexec/urlgrabber-ext-down
#同上，将/usr/bin/python改为/usr/bin/python2三、补充
6.（可有可无）.py在linux上的执行
6.1【直接】python版本 xxx.py
[root@localhost ~]# python test2.py适用于一次性非后台持续运行的测试
6.2【增加权限】chmod + X xxx.py 后 ./xxx.py
[root@localhost ~]# chmod 755 test2.py
[root@localhost ~]# ./test2.py优点：给.py文件设置了权限
缺点：默认指定python执行【如未修改python默认指向，则未python2运行】
6.3【增加权限】chmod + X xxx.py 后 nohup python版本 -u xxxx.py > 日志.log 2>&1 &
[root@localhost ~]# chmod 755 test2.py
[root@localhost ~]# nohup python3.6 -u test2.py > out_test2.log 2>&1 &最为推荐，可在后台持续运行，错误会写进日志
7.（可有可无）暂停.py文件的后台运行【kill (端口号)】
[root@localhost ~]# ps -ef | grep python3.6
root 3701 1949 3 11:01 pts/0 00:00:00 python3.6 -u test2.py
root 3741 1949 0 11:01 pts/0 00:00:00 grep --color=auto python3.6
------------------------------------------------------------------------------
#假设test2.py是正在运行的某监控.py，现在要暂停它
[root@localhost ~]# kill 3701
[root@localhost ~]# ps -ef | grep python3.6
root 4064 1949 0 11:03 pts/0 00:00:00 grep --color=auto python3.6
-----------------------------------------------------------------------------
#已经被kill掉，kill的时候要注意端口号四、常见问题
1.pip版本过低
1.1通过get-pip进行安装
[root@localhost ~]# wget https://bootstrap.pypa.io/pip/3.6/get-pip.py
#截止发布文章，该get-pip地址仍存在，如需其他python版本的pip升级，直接找https://bootstrap.pypa.io/pip/这个网址下的get-pip运行即可
----------------------------------------------------------------------------------
--2022-04-30 21:55:01-- https://bootstrap.pypa.io/pip/3.6/get-pip.py
Resolving bootstrap.pypa.io (bootstrap.pypa.io)...151.101.0.175, 151.101.64.175 ...
2022-04-30 21:55:07 (374 KB/s) - ‘get-pip.py’ saved [2159061/2159061]
-----------------------------------------------------------------------------------
[root@localhost ~]# python get-pip.py
--------------------------------------------------------------------
Collecting pip<22.0
Downloading pip-21.3.1-py3-none-any.whl (1.7 MB)
|████████████████████████████████| 1.7 MB 510 kB/s
Successfully installed pip-21.3.1 wheel-0.37.1
--------------------------------------------------------------------
#注意：！！！下载了哪个版本的get-pip，就用对应的python版本去执行
#我这里python已修改成默认指向python3.6！！！
[root@localhost ~]# pip -V
-------------------------------------------------------------------------
pip 21.3.1 from /usr/local/lib/python3.6/site-packages/pip (python 3.6)
-------------------------------------------------------------------------1.2通过python进行升级
[root@localhost bin]# python -m pip install --upgrade pip -i https://pypi.douban.com/simple
#这里指定了国内的源，下载会比国外源快
---------------------------------------------------------------------------------
Collecting pip
Downloading https://pypi.doubanio.com/packages/a4/6d/6463d49a933f03ae820f8b/pip-21.3.1-py3-none-any.whl (1.7MB)
100% |████████████████████████████████| 1.7MB 985kB/s
Installing collected packages: pip
Found existing installation: pip 9.0.1
Uninstalling pip-9.0.1:
Successfully uninstalled pip-9.0.1
Successfully installed pip-21.3.1
---------------------------------------------------------------------------------
[root@localhost bin]# pip -V
--------------------------------------------------------------------------
pip 21.3.1 from /usr/local/lib/python3.6/site-packages/pip (python 3.6)
--------------------------------------------------------------------------提示：先用whereis pip找下对应pip在哪个版本python，再使用对应版本进行升级！！！
2.编码错误
这个错误在日常运行可能都会遇到，原因是编码方式对中文的支持
2.1SyntaxError: Non-ASCII character ‘\xe5’ in file 1.py on line 2, but no encoding declared
解决方式：
在文件内容开头添加：# -*- coding: UTF-8 -*-2.2UnicodeEncodeError: ‘gbk’ codec can’t encode character ‘\xbb’ in position 227741: illegal multibyte sequence
原因：
这是python3的print()函数自身有限制，不能完全打印所有的unicode字符。
--------------------------------------------------------------
解决方式：
改变标准输出的默认编码，添加如下代码
import io
import sys
sys.stdout = io.TextIOWrapper(sys.stdout.buffer,encoding='utf-8')
如遇乱码（推测是utf-8的兼容性问题），则修改成：
sys.stdout = io.TextIOWrapper(sys.stdout.buffer,encoding='gb18030')提示：以上报错不知道linux是否会出现，这些是之前在win10做python开发时出现的问题！
总结
推荐几个国内源
pip install [包名] -i [pip源]
--------------------------------------------------
清华大学 ：https://pypi.tuna.tsinghua.edu.cn/simple/
阿里云：http://mirrors.aliyun.com/pypi/simple/
中国科学技术大学 ：http://pypi.mirrors.ustc.edu.cn/simple/
华中科技大学：http://pypi.hustunique.com/
豆瓣源：http://pypi.douban.com/simple/
腾讯源：http://mirrors.cloud.tencent.com/pypi/simple
华为镜像源：https://repo.huaweicloud.com/repository/pypi/simple/天上飘来一串神奇的Base64编码：
bXpwMDExMEAxNjMuY29t
VVJMOjgxLjY5LjQuMjI5
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