On 27/10/17 20:05, ROGER GRAYDON CHRISTMAN wrote: > While teaching my introductory course in Python, I occasionally see > submissions containing the following two program lines, even before > I teach about functions and modules: > > if __name__ = '__main__': > ... main() > > When I ask about it, I hear things like they got these from other instructors, > or from other students who learned it from their instructors, or maybe > from some on-line programming tutorial site. > > I'm all on board with the first of these two lines -- and I teach it myself > as soon as I get to modules. > > My question is more about the second. > > Do "real" Pythonista's actually define a new function main() instead > of putting the unit test right there inside the if?
Perhaps not for unit tests, but for scripts, particularly if they come with a larger package, this is actually fairly common: it allows setuptools to generate a wrapper script that runs with the Python version and environment it was installed with. https://python-packaging.readthedocs.io/en/latest/command-line-scripts.html Combined with the way "python -m ..." works, this leads to slightly silly-looking __main__.py modules like this: https://github.com/jupyter/jupyter_core/blob/master/jupyter_core/__main__.py > > Or am I correct in assuming that this main() is just an artifact from > people who have programmed in C, C++, or Java for so long that > they cannot imagine a program without a function named "main"? > > I guess I'm not stuck on that habit, since my programming experiences > go way back to the old Fortran days.... > > > Roger Christman > Pennsylvania State University > -- https://mail.python.org/mailman/listinfo/python-list
