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If any of the modules need to be changed to a different version because a new version is available, change it using requirements and run the install command again:

$ pip install -r requirements.txt

This is also applicable when a new module needs to be included.

At any point, the freeze command can be used to display all installed modules. freeze returns the modules in a format compatible with requirements.txt, making it possible to do this to generate a file with our current environment:

$ pip freeze > requirements.txt

This will include dependencies, so expect a lot more modules in the file.

Finding great third-party modules is not easy sometimes. Searching for specific functionality can work well, but sometimes there are great modules that are a surprise because they do things you never thought of. A great curated list is Awesome Python ( https://awesome-python.com/ ), which covers a lot of great tools for common Python use cases, such as cryptography, database access, date and time handling, and so on.

In some cases, installing packages may require additional tools, such as compilers or a specific library that supports some functionality (for example, a particular database driver). If that's the case, the documentation will normally explain the dependencies.