Introduction to Python Modules

One big question still remains though: how did we know to type from simmate.toolkit import Structure? Here, you should learn to think of python packages (such as Simmate) as many classes and functions organized into folders.

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Conceptual examples

As an example, you can read from simmate.toolkit import Structure as "Inside of the simmate folder, go to the toolkit file and load the Structure class".

Here's a second example: from simmate.toolkit.base_data_types.lattice import Lattice is the same as saying "Go to the simmate folder --> toolkit folder --> base_data_types folder --> lattice.py file --> grab the Lattice class".

So whenever you see an import line, it's just telling you where the actual code is located. All of Simmate's code (and all python codes everywhere) is organized like this.

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A walk-through example

To prove it, let's go through these steps:

1. on Simmate's github homepage, go the src/simmate folder (src = source code)
2. You'll see the toolkit folder that we were using before.
3. Navigate through the folders. simmate --> database --> base_data_types --> calculation.py.
4. You see a Calculation class where all of it's methods and properties are defined.

Each of these folders and files are referred to as python "modules" -- it's just python terminology.

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