OddThinking

Today, I am justifying a particular personal coding standard rule. If I explicitly argue the case, I hope I will conform to it more.

Consider a Python module:


from blah import Blah
from foo import Foo

if __name__ == '__main__':
# This code will only be seen if the package is directly run.
# Not if it is merely imported.
#
# Code that will actually run presumably calling the code in the
# Decl Area.
#
# Let's call this the Main Area.


Code in the Main Area suffers from three short-comings.

• It cannot be re-used by another module.
• It cannot be exercised by a unit test.
• It declares globals, and therefore should use the awkward GLOBALS_NAMING_STANDARD. Oh, and be indented, because it inside an if statement.

Conclusion: Move as much code as possible out of the main area and into the declaration area.

Examples of what I am happy to leave inside the main area:

• Calls to unit-test framework for self-testing modules. The unit-tests themselves should not be here, so they can be called by others.
• Calls to functions to set the Window title (Windows only). That should not apply when the code is re-used.
• Calls to a main() function in the declaration area if this is actually a script that does anything.