When you are into development using Python, you should know how to manager packages and virtual environments. Pip is the package installer in Python and you can use it to install packages from Python Package Index.
If you want to use different versions of a same package in your system, you need to create virtual environments. There are mutiple ways to do that. In this guide, let's see how to use Pipenv
Versions Used
Pip
Pip can be used to install and manage packages which are not part of the standard Python installation. Let's see how to use install and use it now.
Installation
To install pip in your system, open the terminal and type the command
sudo apt install python3-pip
Install python packages
To install a python package using pip, use the command
pip3 install <package_name>
For example, to install the latest version of Django you can use the command
pip3 install django
If you want to install a specific version of a package that is possible too. For example, to install version 2.1.1 of Django you can use the command
pip3 install django==2.1.1
List installed python packages
To see the list of Python packages installed in your system, use the command
pip3 list
This will print the list of packages installed in your system along with their versions. The output will be similar to the one given below.
Package Version
--------------- ----------
appdirs 1.4.3
beautifulsoup4 4.9.1
blinker 1.4
CacheControl 0.12.6
certifi 2019.11.28
chardet 3.0.4
colorama 0.4.3
If you want to see if any of the packages are outdated, use the command
pip3 list -o
This will print the list of packages which can be updated along with the current installed version and the latest version. You can also use the command pip3 list --outdated. Example output is given below.
Package Version Latest Type
----------- ---------- ----------- -----
appdirs 1.4.3 1.4.4 wheel
certifi 2019.11.28 2020.6.20 wheel
contextlib2 0.6.0 0.6.0.post1 wheel
distlib 0.3.0 0.3.1 wheel
distro 1.4.0 1.5.0 wheel
html5lib 1.0.1 1.1 wheel
idna 2.8 2.10 wheel
Freeze requirements
To share the list of packages of your project with others or to push the list to a server, you can use the freeze command as given below
pip3 freeze > requirements.txt
When you run this command, the list of installed packages will captured in the file requirements.txt in the requirements format. The content of the file will be similar to the one given below
appdirs==1.4.3
beautifulsoup4==4.9.1
blinker==1.4
CacheControl==0.12.6
certifi==2019.11.28
chardet==3.0.4
colorama==0.4.3
You can install requirements from a file using the command
pip3 install -r requirements.txt
Note that requirements.txt is the commonly used file name for capturing the package list. But you can also use the file name of your choice.
Help menu
To see the help menu of Pip, use the command
pip3 --help
To see the help menu of a specific command, for example, install command
pip3 install --help
Pipenv
Pipenv can be used to create virtual environments in Python. If you want to use multiple versions of a same Python package in your system, virtual environments are the way to do it. Virtual enviroments can be created and used using multiple methods. Pipenv is one of the easiet ways to do it. Read this guide to learn how to do it using Virtualenv and Virtualenvwrapper.
Install pipenv
Install pipenv using the command
sudo pip3 install pipenv
Create virtual environment
To create a virtual environment using pipenv, install a package using the command pipenv install <package_name>. For example, to install django
pipenv install django
This will create an virtual environment and install the specified package.
Specify python version
To create a virtual environment using specific version of Python, use the command pipenv --python <version>. For example
pipenv --python 3.6
Install requirements
If you have a requirements file, you can install it using the command
pipenv install -r requirements.txt
Install specific version of a package
You can use pipenv install <package_name>==<version> to install a specific version of a package. To install Django 2.1.1, use the command
pipenv install django==2.1.1
Install dev packages
To install packages which will be used only in development environments pass the --dev parameter in the install command. For example
pipenv install django-debug-toolbar --dev
A file named pipfile will be created in your project directory after you create the virtual environment. The file content will be similar the one given below
[[source]]
url = "https://pypi.python.org/simple"
verify_ssl = true
name = "pypi"
[dev-packages]
django-debug-toolbar = "*"
[packages]
django = "==2.1.1"
Activate virtual environment
To activate a virtual environment, use the command
pipenv shell
Remove virtual environment
To remove a virtual environment, use the command
pipenv --rm
You can see a demo of all these commands in the YouTube video given above. Feel free to post your comments.