This guide explains importlib.metadata.version() function: usage and examples through a focused Python example. You will learn the behavior to expect, why it matters in a real program, and how to recognize the common mistakes before applying it in your own project.
What You Will Learn
importlib.metadata.version(distribution_name) returns the installed distribution version from metadata. It does not report the interpreter version and can raise PackageNotFoundError.
When and Why to Use It
The following example focuses on a practical use of importlib.metadata.version() Function: Usage and Examples.
Step-by-Step Example
from importlib.metadata import version, PackageNotFoundError
try:
print(version("distribution_that_is_not_installed_123"))
except PackageNotFoundError:
print("Distribution not installed")Understanding the Example
The intentionally missing distribution demonstrates the documented exception. A real environment may have many installed distributions to query by their published names.
Expected Output
Distribution not installedImportant Behavior and Edge Cases
A distribution name and import module name can differ; use the installation name when querying metadata.
Try It Yourself
Find the version of pip in your active virtual environment and handle a missing installation.
Common Beginner Mistakes
- A distribution name and import module name can differ; use the installation name when querying metadata.
- Assuming that an import has no initialization effects or that every environment resolves modules in the same way.
- Skipping the practice step and assuming the example covers every input. Test at least one normal case and one edge case relevant to this topic.
Key Takeaways
- importlib.metadata.version(distribution_name) returns the installed distribution version from metadata.
- The intentionally missing distribution demonstrates the documented exception.
- Apply the technique deliberately, checking its documented input requirements and failure behavior before integrating it into a larger project.