Aug 15, 2018 The official OpenCV installer does not install the Python bindings into your Python directory. There should be a Python2.7 directory inside your OpenCV 2.2.0 installation directory. Copy the whole Lib folder from OpenCV Python2.7 to C: Python27 and make sure your OpenCV bin directory is in the Windows DLL search path.
In this chapter, you learn how to install Python on MacOS, Windows, and Linux. We will look at multiple installation methods per platform and discuss what I think is the best option to choose from.
Most of the time, it’s not advisable to use the official installer from the python.org website. Instead, it’s better to go for the version packaged by your operating system. The advantage of OS supplied version, is that you’ll get automatic updates.
There are three methods you can choose from on Windows.
Microsoft hosts a community release of Python 3 in the Microsoft Store. This is the recommended way to install Python on Windows because it handles updates automatically and can be uninstalled easily too.
To use this method:
You can download a Python installer from the official Python download website too. This method does not give you automatic updates, and I would recommend it only if you don’t have access to the Microsoft store.
If you’re familiar with Windows Subsystem For Linux, you may want to consider that option too. It’s what I use myself, and I’m truly loving it. It offers me the advantages that Windows has to offer (mainly great hardware support), while still enjoying Linux which is, in my opinion, the best platform for Python development.
To install in WSL, you’ll first need to install WSL itself. Go for WSL2 if you can. It’s much better. After that, simply follow the Linux installation instructions below!
On most versions of MacOS before Catalina, a distribution of Python is already included. Unfortunately, it’s almost certainly an old version, Python 2.7. Luckily, there are two ways to install Python 3 on a Mac with ease.
First and foremost, I recommend looking into Homebrew. It allows you to install almost anything easily. The added benefit is that it’s also easy to upgrade to newer versions later on.
Once you are up and running with homebrew, installing Python on MacOS is as easy as:
Alternatively, you can download an installer from the Python download website. The downside to this approach is that you won’t get automatic updates.
There are several ways to install Python on Linux, that is, if you need to install it at all!
Most Linux distributions include Python. Many will include both Python 2 and Python 3.
If you enter
python --version on the command line, you’ll see the version number. It’s probably version 2.7:
You don’t want Python 2, but some OS’es still ship with it, unfortunately.
python3 --version. If you get a “command not found,” you need to install Python 3. If your output looks similar to this, you’re in luck:
Depending on the distribution of Linux you are running, you can install Python with the default package manager: Yum, APT, etcetera. You’ll need to find out for your specific Linux distribution which package manager is used and how to use it.
If you’re on Ubuntu, Linux Mint, or Debian, you can install using apt:
Another interesting option for Linux is using Homebrew. That’s right, the package manager for Macs also works on Linux.
The major advantages of using Homebrew:
I find myself using Homebrew more and more while working under Linux — give it a try!
If you don’t feel like installing Python, or you are unable to install it for whatever reason, I’ll offer an alternative too: you can use Python right from your browser; no installation necessary!
PyQt is often not installed by default. The PyQt module can be used to create desktop applications with Python. In this article you’ll learn how to install the PyQt module.
The steps to install pip3 are simple and easy to follow. Once you have python 3, use the following command to install pip3: sudo apt-get update sudo apt install python3-pip. Python3 get-pip.py. When you run this command, it installs the applications used to build python modules. Download Mac OS X 64-bit/32-bit x86-64/i386 Installer; Python 2.6.9 - Oct. No files for this release. Python 3.3.2 - May 15, 2013.
Desktop applications made with PyQt are cross platform, they will work on Microsoft Windows, Apple Mac OS X and Linux computers (including Raspberry Pi).
$ sudo apt-get update $ sudo apt-get install python3.8 python3-pip Once the installation is complete, you can run Python 3.8 with the python3.8 command and pip with the pip3 command. Linux Mint and Ubuntu 17 and below: Python 3.8 isn’t in the Universe repository, so you need to get it from a Personal Package Archive (PPA). PyQt is often not installed by default. The PyQt module can be used to create desktop applications with Python. In this article you’ll learn how to install the PyQt module. Desktop applications made with PyQt are cross platform, they will work on Microsoft Windows, Apple Mac OS X and Linux computers (including Raspberry Pi). Doing it Right¶. Let’s install a real version of Python. Before installing Python, you’ll need to install GCC. GCC can be obtained by downloading Xcode, the smaller Command Line Tools (must have an Apple account) or the even smaller OSX-GCC-Installer package.
Related Course:Create GUI Apps with Python PyQt5
To install PyQt on Windows there are a few steps you need to take.
First use the installer from the qt-project website, from qt to install PyQt.
Next you want to install a Python version 3.3 or newer. Check the box to add all of the PyQt5 extras. It’s not necessary to compile everything from source, you can install all the required packages with the installer.
On Python >= 3.6, you can also try this command:
It should work without problems.
On Apple Mac OS X installation is a bit simpler. The first step to take is to install the Mac OS X binary. This installs the PyQt GUI library.
But to use it from Python, you also need Python module. This is where the tool
brew comes in.
You can use brew to install pyqt (in the terminal):
Python is often installed by default on Linux (in nearly all of the distributions including Ubuntu). But you want to make sure to use Python 3, because of all the features and ease of use. You can verify that you have the newest Python version with the command:
On Ubuntu Linux they sometimes include two versions of python,
python. In that case use Python 3.
Once you have Python ready, the next step is to install PyQt.
This isn’t hard to do if you have some Linux experience. You can install PyQt your software package manager. Which package manager to use depends on which Linux distribution you are using.
On Ubuntu Linux / Debian Linux you can use the command:
For CentOS 7 use the command:
For RPM-based systems (Redhat-based)
If you are new to Python PyQt, then I highly recommend this book.
Mac OS X comes with Python 2.7 out of the box.
You do not need to install or configure anything else to use Python 2. Theseinstructions document the installation of Python 3.
The version of Python that ships with OS X is great for learning, but it’s notgood for development. The version shipped with OS X may be out of date from theofficial current Python release,which is considered the stable production version.
Let’s install a real version of Python.
Before installing Python, you’ll need to install GCC. GCC can be obtainedby downloading Xcode, the smallerCommand Line Tools (must have anApple account) or the even smaller OSX-GCC-Installerpackage.
If you already have Xcode installed, do not install OSX-GCC-Installer.In combination, the software can cause issues that are difficult todiagnose.
If you perform a fresh install of Xcode, you will also need to add thecommandline tools by running
xcode-select--install on the terminal.
While OS X comes with a large number of Unix utilities, those familiar withLinux systems will notice one key component missing: a package manager.Homebrew fills this void.
To install Homebrew, open
Terminal oryour favorite OS X terminal emulator and run
The script will explain what changes it will make and prompt you before theinstallation begins.Once you’ve installed Homebrew, insert the Homebrew directory at the topof your
PATH environment variable. You can do this by adding the followingline at the bottom of your
If you have OS X 10.12 (Sierra) or older use this line instead
Now, we can install Python 3:
This will take a minute or two.
pip pointing to the Homebrew’d Python 3 for you.
At this point, you have the system Python 2.7 available, potentially theHomebrew version of Python 2 installed, and the Homebrewversion of Python 3 as well.
will launch the Homebrew-installed Python 3 interpreter.
will launch the Homebrew-installed Python 2 interpreter (if any).
will launch the Homebrew-installed Python 3 interpreter.
If the Homebrew version of Python 2 is installed then
pip2 will point to Python 2.If the Homebrew version of Python 3 is installed then
pip will point to Python 3.
The rest of the guide will assume that
python references Python 3.
The next step is to install Pipenv, so you can install dependencies and manage virtual environments.
A Virtual Environment is a tool to keep the dependencies required by different projectsin separate places, by creating virtual Python environments for them. It solves the“Project X depends on version 1.x but, Project Y needs 4.x” dilemma, and keepsyour global site-packages directory clean and manageable.
For example, you can work on a project which requires Django 1.10 while alsomaintaining a project which requires Django 1.8.
So, onward! To the Pipenv & Virtual Environments docs!
This page is a remixed version of another guide,which is available under the same license.