Why choosing Python as your programming language

Benefits of Python programming language

The main features (and resulting benefits) of the Python programming language (and its two implementations), can be listed as it follows:

• Python is portable, not only on the various flavors of unix, but also on commercial operating systems: MacOS, BeOS, NeXTStep, MS-DOS.. and the various variants of Windows
• Python is free, but it can be used without restriction in commercial projects
• Suitable for both small Python scripts of a few lines of code and complex projects of tens of thousands of lines
• The Python syntax is very simple and, combined with advanced data types (such as lists, dictionaries ..), led to programs which are very compact and readable. At equal functionality, a complete Python program is often 3 to 5 times shorter than a C or C++, or even Java, representing an overall development time of 5 to 10 times shorter and greatly increased ease of maintenance
• Python manages its resources (memory, file descriptors ..) without programmer intervention, by a reference counting mechanism (similar to a garbage collector). There are no explicit pointers in Python
• Python is multi-threaded and multi-processing
• Python is object oriented. It supports multiple inheritance and operator overloading. In its object model, and by taking the C++ terminology, all methods are virtual
• Python Integrates, like Java or newer versions of C++, a system of exceptions handling, which can greatly simplify error control
• Python is dynamic (the interpreter can evaluate strings representing expressions or Python statements), orthogonal (a small number of concepts is sufficient to generate structures very rich), reflective (it supports meta-programming, for example the ability for an object to add or to remove attributes or methods, or even change class running) and introspective (a large number of development tools, such as "debug" or "profiling", are located in Python itself)
• Like Scheme, or Smalltalk, Python is dynamically typed. Any object used by the programmer has a well-defined type at runtime, with no need of any variable advanced declaration
• Python currently has two implementations. One, written in C (interpreted implementation), in which Python programs are compiled into portable instructions, and then executed by a virtual machine (like Java, with one important difference: Java is statically typed, therefore it is much easier to accelerate the execution of a Java program than a Python program). The other, JPython, is written in Java and generates Java bytecode directly
• Python is extensible: as Guile or Tcl; we can easily interface with existing C libraries. One can also use it as an extension language for complex software systems
• The Python standard library, and contributed packages, provides access to a wide variety of services: strings and regular expressions, standard UNIX services (files, pipes, signals, sockets, threads ..), Internet protocols (Web , News, FTP, CGI, HTML ..), data persistence and databases, graphical interfaces
• Python is a language that continues to evolve, supported by a community of enthusiastic users and managers, most of whom are supporters of open source software
• Finally, Python is a language of choice for processing XML documents

Python language versions

Python continues to evolve, but this trend is only intended to improve the language. We will not have to change all our programs to fit a new version that would become incompatible with an earlier one. However there are two development branches: Python 2.x and Python 3.x.

Although Python 3.0 is released shortly after version 2.6, and version 3.1 and 3.2 have been made available in the meantime, few developers have fully switched to the Python 3 branch. This is due to various reasons. The first is that Python 3 has so far brought very few new functionalities, but requires modifying the source code of a project initiated under Python 2.x. The second is that all the major libraries are not yet available for Python 3 branch.

Finally, from the perspective of developers of Python, there were two branches in which new features were added (for instance 2.7 and 3.2), plus two maintenance branches (2.6 and 3.1). In most cases, each commit should be replicated in four branches, which has a significant cost (although some tasks are automated) because the code of each branch has more or less diverged.

Now the new features will be developed only in Python 3 branch. Efforts will therefore concentrate to make latest version more attractive and help porting to Python 3. For example one can view a list of new functionalities Python 3.2 branch. Feature changes in the Python language are handled by the procedure PEP (Python Enhancement Proposals): PEP contains the index of all proposals improvement of Python.

def hello(name):
    print "Hello, {0}!".format(name)
print "The name is:"
name = raw_input()
hello(name)

$ 2to3 example.py

$ 2to3 -w example.py

def hello(name):
    print("Hello, {0}!".format(name))
print("The name is")
name = input()
hello(name)

$ 2to3 -f imports -f has_key example.py