Python in a Nutshell

Chapter 1. Introduction to Python

Python is a general-purpose programming language. It has been around for quite a while: Guido van Rossum, Python’s creator, started developing Python back in 1990. This stable and mature language is very high level, dynamic, object-oriented, and cross-platform—all characteristics that are very attractive to developers. Python runs on all major hardware platforms and operating systems, so it doesn’t constrain your platform choices.

Python offers high productivity for all phases of the software life cycle: analysis, design, prototyping, coding, testing, debugging, tuning, documentation, deployment, and, of course, maintenance. Python’s popularity has seen steady, unflagging growth over the years. Today, familiarity with Python is an advantage for every programmer, as Python is likely to have some useful role to play as a part of any software solution.

Python provides a unique mix of elegance, simplicity, and power. You’ll quickly become productive with Python, thanks to its consistency and regularity, its rich standard library, and the many other modules that are readily available for it. Python is easy to learn, so it is quite suitable if you are new to programming, yet at the same time it is powerful enough for the most sophisticated expert.

The Python Language

The Python language, while not minimalist, is rather spare, for good pragmatic reasons. When a language offers one good way to express a design idea, supplying other ways has only modest benefits, while the cost in terms of language complexity grows with the number of features. A complicated language is harder to learn and to master (and to implement efficiently and without bugs) than a simpler one. Any complications and quirks in a language hamper productivity in software maintenance, particularly in large projects, where many developers cooperate and often maintain code originally written by others.

Python is simple, but not simplistic. It adheres to the idea that if a language behaves a certain way in some contexts, it should ideally work similarly in all contexts. Python also follows the principle that a language should not have convenient shortcuts, special cases, ad hoc exceptions, overly subtle distinctions, or mysterious and tricky under-the-covers optimizations. A good language, like any other designed artifact, must balance such general principles with taste, common sense, and a high degree of practicality.

Python is a general-purpose programming language, so Python’s traits are useful in any area of software development. There is no area where Python cannot be part of an optimal solution. “Part” is an important word here—while many developers find that Python fills all of their needs, Python does not have to stand alone. Python programs can cooperate with a variety of other software components, making it an ideal language for gluing together components written in other languages.

Python is a very-high-level language. This means that Python uses a higher level of abstraction, conceptually farther from the underlying machine, than do classic compiled languages, such as C, C++, and Fortran, which are traditionally called high-level languages. Python is also simpler, faster to process, and more regular than classic high-level languages. This affords high programmer productivity and makes Python an attractive development tool. Good compilers for classic compiled languages can often generate binary machine code that runs much faster than Python code. However, in most cases, the performance of Python-coded applications proves sufficient. When it doesn’t, you can apply the optimization techniques covered in Chapter 17 to enhance your program’s performance while keeping the benefits of high programming productivity.

Python is an object-oriented programming language, but it lets you develop code using both object-oriented and traditional procedural styles, mixing and matching as your application requires. Python’s object-oriented features are like those of C++, although they are much simpler to use.