Running a script via module vs script mode in the BGE

Question

When a script is run via Script mode through the Python Controller there is no need to have import bge in the script.
Why does running a script via Module mode require importing bge?

Documentation on the blender wiki of the differences between script and module modes.

Answer 1

Why does running a script via Module mode require importing bge?

Because the import statement is the proper way of writing Python code.

The auto-import within script mode is a dirty shortcut. It is still there for backward compatibility. But it is no good design.

Pro

• You always need it to access the the BGE context anyway. (In module mode you do not really need it as you can get access via function arguments.)
• Bge is not a real Python module. It is a wrapper around the BGE native code.

Contra

• It violates the Python convention to show where objects are coming from (defined by the code or imported from other modules)
• It hides the fact that this module is imported at all. So a reader will never see an explicit assignment to bge.
• The bge module should behave like regular Python modules, so it should be imported as any other Python module too.

I strongly suggest to add the import statement in script mode too and ignore the auto-import.

I hope it helps