What will occur if you run 'pip3 install pytz' without internet access?

Running 'pip3 install pytz' without internet access will lead to a failure due to the lack of connectivity. This is because the 'pip' tool is designed to retrieve packages from the Python Package Index (PyPI) or other repositories online. If an internet connection is not available, pip cannot access the necessary resources to download the 'pytz' package and its dependencies.

The command relies on downloading the latest version of the specified package over the internet. Therefore, in the absence of an active internet connection, pip cannot fulfill the request, resulting in an error. This situation reinforces the necessity of internet access for package management in Python through pip.