【python初级】 Ubuntu18.04上安装python3、pip3

• 1、背景
• 2、安装python3
• 3、安装pip3

1、背景

最近在使用docker部署。
通过docker镜像创建的容器中没有python3。

Ubuntu18.04系统环境：

root@7a8faaaebdbb:/# cat /proc/version
Linux version 5.4.0-87-generic (buildd@lgw01-amd64-059) (gcc version 7.5.0 (Ubuntu 7.5.0-3ubuntu1~18.04)) #98~18.04.1-Ubuntu SMP Wed Sep 22 10:45:04 UTC 2021
root@7a8faaaebdbb:/# uname -r
5.4.0-87-generic
root@7a8faaaebdbb:/#

2、安装python3

安装命令：apt install python3.6

安装之前执行apt update，更新可用软件包列表。避免出现找不到安装包的报错。

安装细节如下：

root@7a8faaaebdbb:/# apt install python3.6  
Reading package lists... Done
Building dependency tree       
Reading state information... Done
The following additional packages will be installed:
  file libexpat1 libmagic-mgc libmagic1 libmpdec2 libpython3.6-minimal libpython3.6-stdlib mime-support python3.6-minimal
Suggested packages:
  python3.6-venv python3.6-doc binfmt-support
The following NEW packages will be installed:
  file libexpat1 libmagic-mgc libmagic1 libmpdec2 libpython3.6-minimal libpython3.6-stdlib mime-support python3.6 python3.6-minimal
0 upgraded, 10 newly installed, 0 to remove and 15 not upgraded.
Need to get 4528 kB of archives.
After this operation, 27.5 MB of additional disk space will be used.
Do you want to continue? [Y/n] Y
Get:1 http://archive.ubuntu.com/ubuntu bionic-updates/main amd64 libpython3.6-minimal amd64 3.6.9-1~18.04ubuntu1.4 [534 kB]
Get:2 http://archive.ubuntu.com/ubuntu bionic-updates/main amd64 libexpat1 amd64 2.2.5-3ubuntu0.2 [80.5 kB]
Get:3 http://archive.ubuntu.com/ubuntu bionic-updates/main amd64 python3.6-minimal amd64 3.6.9-1~18.04ubuntu1.4 [1610 kB]
Get:4 http://archive.ubuntu.com/ubuntu bionic-updates/main amd64 libmagic-mgc amd64 1:5.32-2ubuntu0.4 [184 kB]
Get:5 http://archive.ubuntu.com/ubuntu bionic-updates/main amd64 libmagic1 amd64 1:5.32-2ubuntu0.4 [68.6 kB]
Get:6 http://archive.ubuntu.com/ubuntu bionic-updates/main amd64 file amd64 1:5.32-2ubuntu0.4 [22.1 kB]
Get:7 http://archive.ubuntu.com/ubuntu bionic/main amd64 libmpdec2 amd64 2.4.2-1ubuntu1 [84.1 kB]
Get:8 http://archive.ubuntu.com/ubuntu bionic/main amd64 mime-support all 3.60ubuntu1 [30.1 kB]
Get:9 http://archive.ubuntu.com/ubuntu bionic-updates/main amd64 libpython3.6-stdlib amd64 3.6.9-1~18.04ubuntu1.4 [1712 kB]
Get:10 http://archive.ubuntu.com/ubuntu bionic-updates/main amd64 python3.6 amd64 3.6.9-1~18.04ubuntu1.4 [203 kB]
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root@7a8faaaebdbb:/# 

python3安装验证
如下安装成功

root@7a8faaaebdbb:/# python
bash: python: command not found
root@7a8faaaebdbb:/# python2
bash: python2: command not found
root@7a8faaaebdbb:/# python3
bash: python3: command not found
root@7a8faaaebdbb:/# python3.6
Python 3.6.9 (default, Jan 26 2021, 15:33:00) 
[GCC 8.4.0] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> 

3、安装pip3

安装命令：apt install python3-pip

安装细节：

root@7a8faaaebdbb:/# apt install python3-pip
Reading package lists... Done
Building dependency tree       
Reading state information... Done
The following additional packages will be installed:
  dbus dh-python gir1.2-glib-2.0 libapparmor1 libdbus-1-3 libexpat1-dev libgirepository-1.0-1 libglib2.0-0 libglib2.0-data libicu60 libpython3-dev libpython3-stdlib
  libpython3.6 libpython3.6-dev libxml2 python-pip-whl python3 python3-asn1crypto python3-cffi-backend python3-crypto python3-cryptography python3-dbus python3-dev
  python3-distutils python3-gi python3-idna python3-keyring python3-keyrings.alt python3-lib2to3 python3-minimal python3-pkg-resources python3-secretstorage python3-setuptools
  python3-six python3-wheel python3-xdg python3.6-dev shared-mime-info xdg-user-dirs
Suggested packages:
  default-dbus-session-bus | dbus-session-bus python3-doc python3-tk python3-venv python-crypto-doc python-cryptography-doc python3-cryptography-vectors python-dbus-doc
  python3-dbus-dbg gnome-keyring libkf5wallet-bin gir1.2-gnomekeyring-1.0 python-secretstorage-doc python-setuptools-doc
The following NEW packages will be installed:
  dbus dh-python gir1.2-glib-2.0 libapparmor1 libdbus-1-3 libexpat1-dev libgirepository-1.0-1 libglib2.0-0 libglib2.0-data libicu60 libpython3-dev libpython3-stdlib
  libpython3.6 libpython3.6-dev libxml2 python-pip-whl python3 python3-asn1crypto python3-cffi-backend python3-crypto python3-cryptography python3-dbus python3-dev
  python3-distutils python3-gi python3-idna python3-keyring python3-keyrings.alt python3-lib2to3 python3-minimal python3-pip python3-pkg-resources python3-secretstorage
  python3-setuptools python3-six python3-wheel python3-xdg python3.6-dev shared-mime-info xdg-user-dirs
0 upgraded, 40 newly installed, 0 to remove and 15 not upgraded.
Need to get 61.4 MB of archives.
After this operation, 139 MB of additional disk space will be used.
Do you want to continue? [Y/n] y^HY^H^H
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pip3安装验证
如下安装成功.

root@7a8faaaebdbb:/# python
bash: python: command not found
root@7a8faaaebdbb:/# python2
bash: python2: command not found
root@7a8faaaebdbb:/# python3
Python 3.6.9 (default, Jan 26 2021, 15:33:00) 
[GCC 8.4.0] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> quit()
root@7a8faaaebdbb:/# python3.6
Python 3.6.9 (default, Jan 26 2021, 15:33:00) 
[GCC 8.4.0] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> quit()
root@7a8faaaebdbb:/# pip
bash: pip: command not found
root@7a8faaaebdbb:/# pip3 list
DEPRECATION: The default format will switch to columns in the future. You can use --format=(legacy|columns) (or define a format=(legacy|columns) in your pip.conf under the [list] section) to disable this warning.
asn1crypto (0.24.0)
cryptography (2.1.4)
idna (2.6)
keyring (10.6.0)
keyrings.alt (3.0)
pip (9.0.1)
pycrypto (2.6.1)
pygobject (3.26.1)
pyxdg (0.25)
SecretStorage (2.3.1)
setuptools (39.0.1)
six (1.11.0)
wheel (0.30.0)
root@7a8faaaebdbb:/#

如上安装了pip3之后，pip3可以使用了。
同时做了python3到python3.6的软链接。