I have installed python3.8
and have found no reference on how to get pip3
to talk to it on ubuntu
. On macos
I had explicitly installed pip3.8
and that has been crucial to getting all packages lined up correctly.
pip3
was installed as follows based on numerous recommendations:
sudo apt-get install python3-pip
But it is pointing to python3.6
:
$ pip3 -V
pip 9.0.1 from /usr/lib/python3/dist-packages [python 3.6]
Please do not suggest anaconda
or venv
: there are reasons we are using directly installed python3.8
.
This guide discusses how to install packages using pip and a virtual environment manager: either venv for Python 3 or virtualenv for Python 2. These are the lowest-level tools for managing Python packages and are recommended if higher-level tools do not suit your needs.
Note
This doc uses the term package to refer to a Distribution Package which is different from an Import Package that which is used to import modules in your Python source code.
Installing pip¶
pip is the reference Python package manager. It’s used to install and update packages. You’ll need to make sure you have the latest version of pip installed.
Unix/macOS
Debian and most other distributions include a python-pip package; if you want to use the Linux distribution-provided versions of pip, see Installing pip/setuptools/wheel with Linux Package Managers.
You can also install pip yourself to ensure you have the latest version. It’s recommended to use the system pip to bootstrap a user installation of pip:
python3 -m pip install --user --upgrade pip python3 -m pip --version
Afterwards, you should have the latest version of pip installed in your user site:
pip 21.1.3 from $HOME/.local/lib/python3.9/site-packages [python 3.9]
Windows
The Python installers for Windows include pip. You can make sure that pip is up-to-date by running:
py -m pip install --upgrade pip py -m pip --version
Afterwards, you should have the latest version of pip:
pip 21.1.3 from c:\python39\lib\site-packages [Python 3.9.4]
Installing virtualenv¶
Note
If you are using Python 3.3 or newer, the
venv
module is the preferred way to create and manage virtual environments. venv is included in the Python standard library and requires no additional installation. If you are using venv, you may skip this section.
virtualenv is used to manage Python packages for different projects. Using virtualenv allows you to avoid installing Python packages globally which could break system tools or other projects. You can install virtualenv using pip.
Unix/macOS
python3 -m pip install --user virtualenv
Windows
py -m pip install --user virtualenv
Creating a virtual environment¶
venv [for Python 3] and virtualenv [for Python 2] allow you to manage separate package installations for different projects. They essentially allow you to create a “virtual” isolated Python installation and install packages into that virtual installation. When you switch projects, you can simply create a new virtual environment and not have to worry about breaking the packages installed in the other environments. It is always recommended to use a virtual environment while developing Python applications.
To create a virtual environment, go to your project’s directory and run
venv. If you are using Python 2, replace venv
with virtualenv
in the below commands.
The second argument is the location to create the virtual environment. Generally, you can just create this in your project and call it env
.
venv will create a virtual Python installation in the env
folder.
Note
You should exclude your virtual environment directory from your version control system using .gitignore
or similar.
Activating a virtual environment¶
Before you can start installing or using packages in your virtual environment you’ll need to activate it. Activating a virtual environment will put the virtual environment-specific python
and pip
executables into your shell’s PATH
.
You can confirm you’re in the virtual environment by checking the location of your Python interpreter:
It should be in the env
directory:
Unix/macOS
Windows
...\env\Scripts\python.exe
As long as your virtual environment is activated pip will install packages into that specific environment and you’ll be able to import and use packages in your Python application.
Leaving the virtual environment¶
If you want to switch projects or otherwise leave your virtual environment, simply run:
If you want to re-enter the virtual environment just follow the same instructions above about activating a virtual environment. There’s no need to re-create the virtual environment.
Installing packages¶
Now that you’re in your virtual environment you can install packages. Let’s install the Requests library from the Python Package Index [PyPI]:
Unix/macOS
python3 -m pip install requests
Windows
py -m pip install requests
pip should download requests and all of its dependencies and install them:
Collecting requests Using cached requests-2.18.4-py2.py3-none-any.whl Collecting chardet=3.0.2 [from requests] Using cached chardet-3.0.4-py2.py3-none-any.whl Collecting urllib3=1.21.1 [from requests] Using cached urllib3-1.22-py2.py3-none-any.whl Collecting certifi>=2017.4.17 [from requests] Using cached certifi-2017.7.27.1-py2.py3-none-any.whl Collecting idna=2.5 [from requests] Using cached idna-2.6-py2.py3-none-any.whl Installing collected packages: chardet, urllib3, certifi, idna, requests Successfully installed certifi-2017.7.27.1 chardet-3.0.4 idna-2.6 requests-2.18.4 urllib3-1.22
Installing specific versions¶
pip allows you to specify which version of a package to install using version specifiers. For example, to
install a specific version of requests
:
Unix/macOS
python3 -m pip install requests==2.18.4
Windows
py -m pip install requests==2.18.4
To install the latest 2.x
release of requests:
Unix/macOS
python3 -m pip install requests>=2.0.0,=2.0.0,