Structure of program development

[Michael Smolen]

Folks:

I am new to this programming adventure. I've gotten past the introductory chapters in 'How to..." books and now want to start developing a much more complicated program that I will use repeated for different applications. When I worked in Perl there was an option to write a program in a text editor, save it, and then run in with Perl. Is such a thing possible in Python? If not, how do I develop a 500+ lines of code?

A second question of the basic design. If I write a program, can I move it to a computer that is without any Python software, or does that machine have to download the Python software? Does Python products contain all parts of a developed program or is it a series of 'call' statements?

Thanks.   Mike