Introduction
The power of Python is the very large amount of libraries that are available online. These libraries can be downloaded to your development environment as packages. Libraries installed on your system system are gradually accumulating and their management could be problematic if there were no adequate tools.
The package management in Python can be really an easy thing if you use the right tools and Pip is one of them.
Pip and PyPI – the Python Package Index
Tutti i pacchetti più utilizzati dalla comunità di sviluppatori in Python vengono raccolti da anni in un repository unico e mondiale chiamato In questo repository, tutti i pacchetti vengono ordinati, documentati e versionati con un opportuno controllo per le dipendenze.
All the packages used by the community of developers in Python are collected for years in a single repository called PyPI (Python Package Index). In this repository, all packages are sorted, documented and versioned with a suitable control for all dependencies.
PIP is an essential tool that allows you to download, update (synchronize virtually) all of the repository packages you need, taking care to check the proper dependencies and the compatibility among versions
Pip installation
Generally in most distributions of Python, pip should already be included. In fact, for all versions of Python 2> 2.7.9 and Python 3> 3.4, pip is already installed. Same thing if you have created a virtual environment with virtualenv or pyenv.
Installation is simple
On Ubuntu and Debian
$ sudo apt-get install python-pip
On Fedora
$ sudo yum install python-pip
On Mac
$ sudo easy_install pip
But if it were not so, you can install it by downloading a script in Python specially created and then run it.
wget https://bootstrap.pypa.io/get-pip.py python get-pip.py
Using PIP – Commands
Pips, in addition to being very useful, it is also very simple to use. From the command line, Just write pip followed by an option (command) which is nothing but the task that we want him to do.
Installing a package
For example, to install a package, simply write
pip install nomepacchetto
Pip will connect with the repository, then perform a search to find the package you requested. It will check if there is a version compatible with your version of Python and with the operating system you are using.
Then it will ask you for confirmation if you want to install with classic choice Yes or No. Then if confirm the installation will begin to install the package and any other packages which are required for its operation.
Uninstall a package
Removing a package is even easier
pip uninstall nomepacchetto
List installed packages
To get the list of installed packages on your system
pip freeze
or
pip list
Search for a particular package in the repository PyPI
Finally if you want to know both the existence and the information of a given packet within the PyPI repository without having to install it, you write the following command:
pip show nomepacchetto
update PIP
However Python is a language that is experiencing great excitement and then every month there are always a number of new releases, including PIP. So it is important to check if PIP itself is upgraded to the latest version
To update PIP simply write
pip install --upgrade pip
and the system will begin to write the following commands
You are using pip version 6.1.1, however version 9.0.1 is available. You should consider upgrading via the 'pip install --upgrade pip' command. C:\Users\Fabio\Anaconda\lib\site-packages\pip\_vendor\requests\packages\urllib3\util\ssl_.py:79: InsecurePlatformWarning: A true SSLContext object is not available. This prevents urllib3 from configuring SSL appropriately and may cause certain SSL connections to fail. For more information, see https://urllib3.readthedocs.org/en/latest/security.html#insecureplatformwarning. InsecurePlatformWarning Collecting pip Downloading pip-9.0.1-py2.py3-none-any.whl (1.3MB) 100% |################################| 1.3MB 264kB/s Installing collected packages: pip Found existing installation: pip 6.1.1 DEPRECATION: Uninstalling a distutils installed project (pip) has been deprecated and will be removed in a future version. This is due to the fact that uninstalling a distutils project will only partially uninstall the project. Uninstalling pip-6.1.1: Successfully uninstalled pip-6.1.1 Failed to write executable - trying to use .deleteme logic Successfully installed pip-9.0.1
Once you have updated PIP, you’ll know which packages have newer versions than those currently installed on your system
pip list --outdated --format=columns
You will get a table with the name of a package, the current version installed on your system and the latest version in the repository
Package Version Latest Type ---------------------------- ------- ----------- ----- argcomplete 0.8.1 1.7.0 wheel astropy 0.4.2 1.3 sdist atom 0.3.9 0.3.10 sdist backports.ssl-match-hostname 3.4.0.2 3.5.0.1 sdist beautifulsoup4 4.3.2 4.5.3 wheel
Update all packages or packages with a single command
it is strange but true, there is no simple and direct command to update all packages that we have installed on our system. So?
Well there is a fairly complex line with a pipe of different commands that allows you to do this:
pip freeze --local | grep -v '^\e' | cut -d = -f 1 | xargs -n1 pip install -U
and the system will begin to update a package after the other. This may take several minutes.[:]