Checking installed modules in python

How to Easily See All Python Modules Installed on Your System

Learn how to easily see all Python modules installed on your system with this comprehensive guide. Explore different methods, including package managers and commands like ‘pip list’ and ‘pip freeze’.

• Package Managers for Listing Installed Python Packages
• Using ‘help(’modules’)’ Command in IPython Shell
• How To List Installed Python Packages using pip command form
• ‘pip list’ Command to List All Installed Python Packages
• ‘pip freeze’ Command to List All Installed Packages and Their Versions
• Other Helpful Commands for Listing Installed Python Packages
• Other simple code samples for viewing all installed Python modules
• Conclusion
• How do I see all Python modules installed?
• How can I get a list of installed modules?
• How do I see all installed pip packages?
• How do I find where Python packages are installed?

Python is a popular programming language that offers a wide range of packages and modules for various applications. However, it can be challenging to keep track of all the installed modules on your system. This article provides a comprehensive guide on how to see all Python modules installed on your system.

Package Managers for Listing Installed Python Packages

Package managers are tools that can be used to list Installed Python Packages. There are several popular package managers that can be used for this purpose, including Pip, Pipenv, Anaconda Navigator, and Conda.

Pip

Pip is a command-line tool for installing and managing Python packages that can be used to list all installed packages and their versions. To see all installed packages using Pip, open a terminal or command prompt and enter the following command:

This will display a list of all the installed packages, along with their specific version and location. Python packages installed using the pip command are stored under the /usr/local/lib/ /dist-packages/pip/ directory in Linux.

Pipenv

Pipenv is a tool that provides virtual environments for python projects and can be used to list installed packages. To see all installed packages using Pipenv, navigate to the project directory and enter the following command:

This will display a list of all the installed packages, along with their dependencies and version numbers.

Anaconda Navigator

Anaconda Navigator is a graphical user interface (GUI) for managing packages and can be used to list globally and locally installed packages. To see all installed packages using Anaconda Navigator, open the application and navigate to the Environments tab. This will display a list of all the installed packages in the selected environment, along with their dependencies and version numbers.

Conda

Conda is a cross-platform package manager and environment management system that can be used to list installed packages. To see all installed packages using Conda, open a terminal or command prompt and enter the following command:

This will display a list of all the installed packages, along with their dependencies and version numbers.

Using ‘help(’modules’)’ Command in IPython Shell

The ‘help(’modules’)’ command can be used in the IPython shell to list all installed modules and their versions. To use this command, open an IPython shell and enter the following command:

This will display a comprehensive list of all the installed modules, including built-in modules and third-party modules. The modules are listed alphabetically and can be scrolled through using the arrow keys.

How To List Installed Python Packages using pip command form

In this video, you will see How To List Installed Python Packages using pip command form Duration: 1:02

‘pip list’ Command to List All Installed Python Packages

The ‘pip list’ command is a popular method for listing all installed Python packages. This command can be used in the terminal or Python shell to list all the installed packages, along with their specific version and location. Python packages installed using the pip command are stored under the /usr/local/lib/ /dist-packages/pip/ directory in Linux.

By default, the ‘pip list’ command shows the packages installed in Python 2.7. However, it can be used with a specific version of Python to show packages installed in that version. For example, to see packages installed in Python 3.8, enter the following command:

The ‘pip freeze’ command can be used to list all installed packages and their versions, which can also be used to recreate the environment on another machine. This command generates a list of all the installed packages and their versions in a format that can be used in requirements files. The ‘pip freeze’ command is commonly used for sharing project dependencies with other developers.

To use the ‘pip freeze’ command, open a terminal or command prompt and enter the following command:

This will display a list of all the installed packages and their versions.

Other Helpful Commands for Listing Installed Python Packages

There are several other commands that can be used to list installed python packages, including the ‘show your_package’ command and the ‘sys.path()’ command.

The ‘show your_package’ command can be used to find the installation location of a package. To use this command, open a terminal or command prompt and enter the following command:

This will display information about the package, including its installation location.

The ‘sys.path()’ command in Python can be used to show all the paths for Python, including where modules are stored. To use this command, open a Python shell and enter the following command:

This will display a list of all the paths that Python searches for modules.

Other simple code samples for viewing all installed Python modules

# this will show where numpy is installed pip show numpy

In Python as proof, list all installed Python modules code sample

Conclusion

In conclusion, there are multiple ways to list all Python modules installed on your system, including using package managers, the ‘help(’modules’)’ command, ‘pip list’ command, and ‘pip freeze’ command. It is important to keep track of installed packages and modules for efficient development and troubleshooting. best practices for managing python packages include using virtual environments and requirements files, and common issues with python packages include version conflicts and package dependency issues. By following the methods outlined in this article, you can easily see all Python modules installed on your system and ensure that your Python projects are running smoothly.

Frequently Asked Questions — FAQs

What is the importance of keeping track of installed Python modules?

Keeping track of installed Python modules is crucial for efficient development and troubleshooting. This ensures that your code runs smoothly and minimizes the chances of encountering errors caused by missing or incompatible modules.

How can I find the installation location of a specific Python package?

You can use the ‘show your_package’ command to find the installation location of a package. This is useful when you need to modify or remove a package from your system.

What are some best practices for managing Python packages?

Best practices for managing Python packages include using virtual environments and requirements files. Virtual environments allow you to isolate dependencies and ensure that your code runs consistently across different systems. Requirements files make it easy to share and reproduce your project dependencies.

What are some common issues with Python packages?

Common issues with Python packages include version conflicts and package dependency issues. Version conflicts occur when different packages require different versions of the same module. Package dependency issues occur when a package requires another package that is not installed or is incompatible with other installed packages.

How can I recreate an environment with the same installed packages on another machine?

You can use the ‘pip freeze’ command to generate a list of all the installed packages and their versions in a format that can be used in requirements files. You can then use this file to recreate the environment on another machine.

Can I use ‘pip list’ to show packages installed in a specific version of Python?

Yes, you can use the ‘python -3.8 -m pip list’ command to show packages installed in a specific version of Python. Replace ‘3.8’ with the desired version number.

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Checking installed modules in python

Last updated: Feb 23, 2023
Reading time · 3 min

# Table of Contents

# Check if a Python package is installed

To check if a Python package is installed:

1. Import the package in a try block.
2. Use an except block to handle the potential ModuleNotFoundError .
3. If the try block runs successfully, the module is installed.

Copied! 
try: import requests print('The requests module is installed') except ModuleNotFoundError: print('The requests module is NOT installed') 

We used a try/except block to check if a module is installed.

If the try block doesn’t raise an exception, the module is installed.

If the module isn’t installed, a ModuleNotFoundError error is raised and the except block runs.

# Installing the module if it isn’t already installed

You can also extend the try/except statement to install the module if it isn’t installed.

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import sys import subprocess try: import requests print('The requests module is installed') except ModuleNotFoundError: print('The requests module is NOT installed') # 👇️ optionally install module python = sys.executable subprocess.check_call( [python, '-m', 'pip', 'install', 'requests'], stdout=subprocess.DEVNULL ) finally: import requests 

If you need to check if a package is installed using pip , use the pip show command.

The pip show module_name command will either state that the package is not installed or show a bunch of information about the package, including the location where the package is installed.

You can also use the following one-liner command.

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python -c 'import pkgutil; print(1 if pkgutil.find_loader("module_name") else 0)' 

Make sure to replace module_name with the actual name of the module you are checking for.

The command returns 1 if the module is installed and 0 if it isn’t but this can be easily adjusted.

# Check if a Python package is installed using find_spec

An alternative approach is to use the importlib.util.find_spec method.

The find_spec() method will return a spec object if the module is installed, otherwise, None is returned.

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import importlib.util module_name = 'requests' spec = importlib.util.find_spec(module_name) if spec: print(f'The module_name> module is installed') else: print(f'The module_name> module is NOT installed') 

The importlib.util.find_spec method finds the spec for a module.

The spec for a module is a namespace containing the import-related information used to load the module.

If no spec is found, the method returns None.

# Installing the package if it isn’t already installed

You can optionally install the package if it isn’t already installed.

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import importlib.util import sys import subprocess module_name = 'requests' spec = importlib.util.find_spec(module_name) if spec: print(f'The module_name> module is installed') else: print(f'The module_name> module is NOT installed') # 👇️ optionally install the module if it's not installed python = sys.executable subprocess.check_call( [python, '-m', 'pip', 'install', 'requests'], stdout=subprocess.DEVNULL ) 

# Checking if the module isn’t installed

If you need to check if the module isn’t installed, check if the spec variable stores a None value.

Copied! 
import importlib.util import sys import subprocess module_name = 'requests' spec = importlib.util.find_spec(module_name) if spec is None: print(f'The module_name> module is NOT installed') # 👇️ optionally install the module if it's not installed python = sys.executable subprocess.check_call( [python, '-m', 'pip', 'install', 'requests'], stdout=subprocess.DEVNULL ) print(f'The module_name> module is now installed') 

Which approach you pick is a matter of personal preference. I’d use the try/except statement because I find it quite direct and easy to read.

# Additional Resources

You can learn more about the related topics by checking out the following tutorials:

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