What is the role of the poetry.lock file in managing dependencies in a Python project?

The poetry.lock file records the exact versions of all project dependencies, including transitive dependencies (dependencies of dependencies). This guarantees that when dependencies are installed on different machines or at different times, the same package versions will be used, ensuring reproducibility of the environment and stability of the application.

Essentially, poetry.lock serves as a snapshot of the current dependency state, which Poetry uses to install exactly those versions that have been tested and fixed.