A Python program and/or module is easy to create and has a simple form. Just add the code.

I typically use the program and module form of the following, for, say, a main file and a module file.

• rmsMain.py for the module file.
• main1.py for the main file which uses and/or tests rmsMain.py

Actually, I use a formatter system so main2.py gets formatted to rmsMain.py (and possibly other files), which is how I got started with this model.

Another model is to use the __main__ built-in variable. Many programmers like this model as it allows the concept of a module to be combined with test and/or other code - but only if the Python program/script is the top-level script. This is detected via the __main__ built-in variable.

Note that a Python program/script called __main__.py as part of a package would be executed if the module is run with the -m parameter.

Here is the Python script without __main__.

Here is the Python code [#1]
print("Hello")
Here is the output of the Python code.
Hello

Here is the Python script with __main__.

Here is the Python code [#2]
if __name__ == "__main__": print("Hello")
Here is the output of the Python code.
Hello

The Python script without __main__ is cleaner, especially for beginning students.

The Python script with __main__ facilitates unit testing and reduces the number of file as projects grow larger.

The Python script with __main__ also helps make Python scripts model more closely (if that is important) languages such as C, C++, Java, C#, etc. where there needs to be a main function.