All software development, Python or otherwise, above a certain level of complexity follows repeatable patterns, or has a life cycle. A Software (or System) Development Life-Cycle (SDLC) might be used as its own distinct development methodology, providing a set of tasks and activities that apply to the development process. That is, even if there is no formal process wrapped around an SDLC, any or all of the activities that go on through one may still take place, and any or all of the artifacts that come out of them may be available during the development of a project.
From the perspective of the actual development, not all of the artifacts resulting from an SDLC, formal or otherwise, may be significantly useful, either, particularly those coming out of the first few phases of the life cycle's process. Even so, the more knowledge that...