Learn Python Programming

At this point, you should have a clearer picture of how Python works than when you started. Now the rubber hits the road, so to speak, and in the next ten chapters you put your newfound skills to work. Each chapter contains a single do-it-yourself project with a lot of room for experimentation, while at the same time giving you the necessary tools to implement a solution. In this chapter, I give you some general guidelines for programming in Python. Why Playful?  I think one of the strengths of Python is that it makes programming fun—for me, anyway. It’s much easier to be productive when you’re having fun; and one of the fun things about Python is that it allows you to be very productive. It’s a positive feedback loop, and you get far too few of those in life.     The expression Playful Programming is one I invented as a less extreme version of Extreme Programming, or XP.1 I like many of the ideas of the XP movement but have been too lazy to commit completely to...

Once your program is ready for release, you will probably want to package it properly before distributing it. If it consists of a single .py file, this might not be much of an issue. If you’re dealing with nonprogrammer users, however, even placing a simple Python library in the right place or fiddling with the PYTHONPATH may be more than they want to deal with. Users normally want to simply double-click an installation program, follow some installation wizard, and then have your program ready to run.     Lately, Python programmers have also become used to a similar convenience, although with a slightly more low-level interface. The Setuptools toolkit, and the older Distutils, for distributing Python packages makes it easy to write install scripts in Python. You can use these scripts to build archive files for distribution, which the programmer (user) can then use for compiling and installing your libraries.     In this tutorial, I focus on Setuptools, b...

In this rather short chapter, you’ll learn the basics of how to make graphical user interfaces (GUIs) for your Python programs—you know, windows with buttons and text fields and stuff like that. The de facto standard GUI toolkit for Python is Tkinter, which ships as part of the standard Python distribution. Several other toolkits are available, however. This has its advantages (greater freedom of choice) and drawbacks (others can’t use your programs unless they have the same GUI toolkit installed). Fortunately, there is no conflict between the various GUI toolkits available for Python, so you can install as many different GUI toolkits as you want.      This tutorial gives a brief introduction to using Tkinter, and we’ll build on this in another Tutorial. Tkinter is easy to use, but there’s a lot to learn if you want to use all of its features. I’ll only scratch the surface here to get you going; for further details, you should consult the section on graphical user ...

So far, we’ve mainly been working with data structures that reside in the interpreter itself. What little interaction our programs have had with the outside world has been through input and print. In this chapter, we go one step further and let our programs catch a glimpse of a larger world: the world of files and streams. The functions and objects described in this chapter will enable you to store data between program invocations and to process data from other programs. Opening Files  You can open files with the open function, which lives in the io module but is automatically imported for you. It takes a file name as its only mandatory argument and returns a file object. Assuming that you have a text file (created with your text editor, perhaps) called somefile.txt stored in the current directory, you can open it like this: >>> f = open('somefile.txt') You can also specify the full path to the file, if it’s located somewhere else. If it doesn’t exist, however, ...