Python main call within class

Question

I haven’t done much python – coming from a C/Java background – so excuse me for asking such a simple question. I am using Pydev in Eclipse to write this simple program, and all I want it to do is to execute my main function:

class Example():

if __name__ == '__main__':
    Example().main()        <----- What goes here?


    def main(self):     
        print "Hello World!

That is what I have now. I have also tried

self.main()

and

main()

and

main(self)

none of which work. What am I missing?

Asked By: franka

||

Source

Answer 1

That entire block is misplaced.

class Example(object):
    def main(self):     
        print "Hello World!"

if __name__ == '__main__':
    Example().main()

But you really shouldn’t be using a class just to run your main code.

Answered By: Ignacio Vazquez-Abrams

Answer 2

Well, first, you need to actually define a function before you can run it (and it doesn’t need to be called main). For instance:

class Example(object):
    def run(self):
        print "Hello, world!"

if __name__ == '__main__':
    Example().run()

You don’t need to use a class, though – if all you want to do is run some code, just put it inside a function and call the function, or just put it in the if block:

def main():
    print "Hello, world!"

if __name__ == '__main__':
    main()

or

if __name__ == '__main__':
    print "Hello, world!"

Answered By: Amber

Answer 3

Remember, you are NOT allowed to do this.

class foo():
    def print_hello(self):
        print("Hello")       # This next line will produce an ERROR!
    self.print_hello()       # <---- it calls a class function, inside a class,
                             # but outside a class function. Not allowed.

You must call a class function from either outside the class, or from within a function in that class.

Answered By: Dr. Robert Brownell

Python main call within class

Question:

Answers: