如何在 ubuntu 14.04 上将 python3.6 设为默认值答案

【问题标题】：How to make python3.6 as default on ubuntu 14.04如何在 ubuntu 14.04 上将 python3.6 设为默认值
【发布时间】：2019-07-02 02:09:31
【问题描述】：

Ubuntu 14.04安装了3个python版本2.7/3.4/3.6；

$ lsb_release -a
No LSB modules are available.
Distributor ID: Ubuntu
Description:    Ubuntu 14.04.5 LTS
Release:        14.04
Codename:       trusty

python3 默认运行 3.4。

$ python3
Python 3.4.3 (default, Nov 28 2017, 16:41:13)
[GCC 4.8.4] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>>

我想将 python 3.6 设为默认。我该怎么做？其次，由于 python3.4 是默认的，pip3 使用它并且无法安装更令人担忧的 slackclient 模块

$ sudo pip3 install slackclient
Downloading/unpacking slackclient
  Downloading slackclient-2.1.0-py2.py3-none-any.whl (51kB): 51kB downloaded
Downloading/unpacking aiohttp>3.5.2 (from slackclient)
  Downloading aiohttp-3.5.4.tar.gz (1.1MB): 1.1MB downloaded
  Running setup.py (path:/tmp/pip_build_root/aiohttp/setup.py) egg_info for package aiohttp
    Traceback (most recent call last):
      File "<string>", line 17, in <module>
      File "/tmp/pip_build_root/aiohttp/setup.py", line 13, in <module>
        raise RuntimeError("aiohttp 3.x requires Python 3.5.3+")
    RuntimeError: aiohttp 3.x requires Python 3.5.3+
    Complete output from command python setup.py egg_info:
    Traceback (most recent call last):

  File "<string>", line 17, in <module>

  File "/tmp/pip_build_root/aiohttp/setup.py", line 13, in <module>

    raise RuntimeError("aiohttp 3.x requires Python 3.5.3+")

RuntimeError: aiohttp 3.x requires Python 3.5.3+

----------------------------------------
Cleaning up...

非常感谢任何帮助。

我看到 python3 符号链接到 python3.4，不确定更改是否会有所帮助，因为这是一个生产系统，所以我不想做任何我不知道的事情。

/usr/bin$ ls -l python3.4*
-rwxr-xr-x 2 root root 3714088 Nov 28  2017 python3.4
lrwxrwxrwx 1 root root      33 Nov 28  2017 python3.4-config -> x86_64-linux-gnu-python3.4-config
-rwxr-xr-x 2 root root 3714088 Nov 28  2017 python3.4m
lrwxrwxrwx 1 root root      34 Nov 28  2017 python3.4m-config -> x86_64-linux-gnu-python3.4m-config

【问题讨论】：

unix.stackexchange.com/questions/410579/…

标签： python python-3.x ubuntu

【解决方案1】：

其实这行得通；

$ sudo pip3 install --upgrade pip
Downloading/unpacking pip from https://files.pythonhosted.org/packages/5c/e0/be401c003291b56efc55aeba6a80ab790d3d4cece2778288d65323009420/pip-19.1.1-py2.py3-none-any.whl#sha256=993134f0475471b91452ca029d4390dc8f298ac63a712814f101cd1b6db46676
  Downloading pip-19.1.1-py2.py3-none-any.whl (1.4MB): 1.4MB downloaded
Installing collected packages: pip
  Found existing installation: pip 1.5.4
    Not uninstalling pip at /usr/lib/python3/dist-packages, owned by OS
Successfully installed pip
Cleaning up...
$ sudo pip3 install slackclient
DEPRECATION: Python 3.4 support has been deprecated. pip 19.1 will be the last one supporting it. Please upgrade your Python as Python 3.4 won't be maintained after March 2019 (cf PEP 429).
WARNING: The directory '/home/blah/.cache/pip/http' or its parent directory is not owned by the current user and the cache has been disabled. Please check the permissions and owner of that directory. If executing pip with sudo, you may want sudo's -H flag.
WARNING: The directory '/home/blah/.cache/pip' or its parent directory is not owned by the current user and caching wheels has been disabled. check the permissions and owner of that directory. If executing pip with sudo, you may want sudo's -H flag.
Collecting slackclient
  Downloading https://files.pythonhosted.org/packages/7c/2f/9b6db4c7686be3dc6b4244eaef4f37226a2ccca1a796516d4adcdfeefe56/slackclient-1.3.2.tar.gz
Collecting websocket-client<0.55.0,>=0.35 (from slackclient)
  Downloading https://files.pythonhosted.org/packages/26/2d/f749a5c82f6192d77ed061a38e02001afcba55fe8477336d26a950ab17ce/websocket_client-0.54.0-py2.py3-none-any.whl (200kB)
     |████████████████████████████████| 204kB 2.3MB/s
Requirement already satisfied: requests<3.0a0,>=2.11 in /usr/local/lib/python3.4/dist-packages (from slackclient) (2.13.0)
Requirement already satisfied: six<2.0a0,>=1.10 in /usr/local/lib/python3.4/dist-packages (from slackclient) (1.10.0)
Building wheels for collected packages: slackclient
  Building wheel for slackclient (setup.py) ... done
  Stored in directory: /home/blah/.cache/pip/wheels/3b/d4/92/3458f0e1a3e1a9c8935d3b2db89a75d74d8d45601fedec752f
Successfully built slackclient
Installing collected packages: websocket-client, slackclient
Successfully installed slackclient-1.3.2 websocket-client-0.54.0

【讨论】：