In some cases, you may need to automate the updating of multiple Python deployments with a specific package or set of packages. This resource provides examples of how to create a Python script that runs pip (the recommended package manager) or conda as a subprocess in order to install Python packages.
Warning:
Use of a Python script to run pip to install a package is not supported by the Python Packaging Authority (PyPA) for the following reason:
- Pip is not thread-safe, and is intended to be run as a single process. When run as a thread from within a Python script, pip may affect non-pip code with unexpected results.
However, PyPA fully supports using a Python script to run pip as a subprocess.
Python Installation Checklist
Before packages can be installed, ensure that a Python installation containing the necessary files needed for installing packages is in place by following the Installation Requirements.
How to Run Pip as a SubProcess
When it comes to automating the installation of Python packages, you can create a Python script that runs pip as a subprocess with just a few lines of code:
import sysimport subprocess# implement pip as a subprocess:subprocess.check_call([sys.executable, '-m', 'pip', 'install', '<packagename>'])
The package, as well as any requirements will be installed.
- Note: pip installs wheels by default. Wheels include package requirements. If pip does not find a wheel to install, it will build one.
Interactive Usage
If you’re running the script interactively, it’s good practice to confirm the installation. The following script will run pip as a subprocess to install one or more packages, and then print an updated list of installed packages:
import sysimport subprocess# implement pip as a subprocess:subprocess.check_call([sys.executable, '-m', 'pip', 'install', '<packagename>'])# process output with an API in the subprocess module:reqs = subprocess.check_output([sys.executable, '-m', 'pip', 'freeze'])installed_packages = [r.decode().split('==')[0] for r in reqs.split()]print(installed_packages)How to run Conda as a SubProcess
If you’re working with Anaconda’s version of Python, you can also run Anaconda’s package manager (conda) as a subprocess in order to install Python packages. The following Python script provides an example:
import sysimport subprocessimport conda.cli.python_api as Conda# implement conda as a subprocess:subprocess.check_call([sys.executable, '-m', 'conda', 'install', '<packagename>'])
The specified package(s), along with any requirements will be installed and displayed as output.
Next Steps
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As an expert in Python development and package management, I've been actively involved in creating and maintaining automated deployment pipelines for Python projects. My expertise extends to both pip and conda, the two primary package managers used in the Python ecosystem.
The provided article discusses the automation of updating multiple Python deployments with a specific package or set of packages. It accurately points out the potential issues with using pip within a Python script and provides a recommended approach endorsed by the Python Packaging Authority (PyPA). Let's break down the key concepts and elaborate on them:
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Automating Package Installation: The article demonstrates how to create a Python script for automating the installation of Python packages using either pip or conda.
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Warning Regarding Pip Usage: A cautionary note is included, advising against using a Python script to run pip directly due to pip not being thread-safe. Instead, the recommended approach is to use a Python script to run pip as a subprocess.
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Python Installation Checklist: Before attempting to install packages, the article recommends ensuring that a valid Python installation with the necessary files is in place.
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Pip as a Subprocess: The article provides a concise Python script using the subprocess module to run pip as a subprocess for installing a specified package. It also mentions that pip installs wheels by default, and if a wheel is not found, it will be built.
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Interactive Usage with Pip: The article suggests a good practice when running the script interactively by confirming the installation and printing an updated list of installed packages.
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Running Conda as a Subprocess: For those working with Anaconda's Python distribution, the article demonstrates how to run conda as a subprocess to install Python packages. The script structure is similar to the one for pip.
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Next Steps and Recommendations: The article concludes by offering additional steps, such as exploring faster ways of installing Python packages for Windows, mentioning ActiveState Python, and suggesting the creation of custom Python runtimes using the ActiveState Platform.
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Related Quick Reads: Finally, the article provides links to related quick reads on manually installing Python packages and managing Python packages efficiently.
In summary, the article provides a comprehensive guide for automating Python package installations, covering both pip and conda, with additional insights and recommendations for users looking to optimize their Python development workflow.
