The very first one, "Make a script both importable and executable," needs some caveats. It's useful sometimes, but people often use it in places where it is no

The very first one, "Make a script both importable and executable," needs some caveats. It's useful sometimes, but people often use it in places where it is not a great idea. Here's why: 1) If you are in the mindset of "I want a single file which is both a library and a program," how will you name it? Files to import must end with ".py" and follow C-style name rules, so cannot start with a number cannot contain hyphens. This leads many people to break conventions when naming their programs, because on Unix, hyphens are conventional in program names but underscores are not (count the examples of each in /usr/bin on any system). And naming your program something like "2to3" is impractical if you want it to be importable also. 2) It is unclear where to install files which are both programs and libraries. Programs usually go in some sort of "bin" directory (again, on Unix systems), but libraries do not. Where do you put a file which is both? 3) Sometimes the __name__ == '__main__' trick is used to include unit tests within a module. That's not bad, but consider using Python's excellent doctest feature instead, which often serves the same need but in a richer way.